diff --git a/cmd/protoc-gen-tarantool/internal/gen/gen.go b/cmd/protoc-gen-tarantool/internal/gen/gen.go
index 8de1de4023f851622353ddf256776f245521c575..a6861eff4374f29d42808d343ad888b30e7c733a 100644
--- a/cmd/protoc-gen-tarantool/internal/gen/gen.go
+++ b/cmd/protoc-gen-tarantool/internal/gen/gen.go
@@ -181,6 +181,7 @@ 	// Hot-path locals used by the inlined tag/length fast paths in each
 	// generated _decode function. Localizing turns the LuaJIT references
 	// into upvalue reads on the trace instead of repeated global lookups.
 	w.line("local string_byte = string.byte")
+	w.line("local utf8_len = require('utf8').len")
 	w.line("local band = bit.band")
 	w.line("local rshift = bit.rshift")
 }
diff --git a/cmd/protoc-gen-tarantool/internal/gen/inline.go b/cmd/protoc-gen-tarantool/internal/gen/inline.go
index 73378569881e359ecfe386a4de1cf8adae46d828..8a0182266237309d26d1f082904a1af5d0ef5eb7 100644
--- a/cmd/protoc-gen-tarantool/internal/gen/inline.go
+++ b/cmd/protoc-gen-tarantool/internal/gen/inline.go
@@ -505,9 +505,19 @@ 		w.line("            u, pos = wire.decode_varint(buf, pos)")
 		w.line("            %s = wire.varint_to_int32(u)", luaFieldAccess("result", fname))
 	default:
 		st := scalarName(f.Desc.Kind())
-		w.line("            local val")
-		w.line("            val, pos = wire.decode_%s(buf, pos)", st)
-		w.line("            %s = val", luaFieldAccess("result", fname))
+		if st == "string" || st == "bytes" {
+			// Inline the 1-byte LEN fast path (length < 128). Skips the
+			// `wire.decode_string` / `wire.decode_bytes` function call
+			// frame for the typical short-string case; the resulting
+			// straight-line code stays inside the parent JIT trace
+			// instead of stitching through a child trace. (a6n)
+			dst := luaFieldAccess("result", fname)
+			emitInlineStringBytesScalar(w, st, dst)
+		} else {
+			w.line("            local val")
+			w.line("            val, pos = wire.decode_%s(buf, pos)", st)
+			w.line("            %s = val", luaFieldAccess("result", fname))
+		}
 	}
 
 	// Oneof: clear sibling branches so callers see exactly one set field.
@@ -577,11 +587,53 @@ 			w.line("                val, pos = wire.decode_%s(buf, pos)", st)
 			w.line("                %s = %s + 1; list[%s] = val", cnt, cnt, cnt)
 			w.line("            end")
 		} else {
-			w.line("            local val")
-			w.line("            val, pos = wire.decode_%s(buf, pos)", st)
-			w.line("            %s = %s + 1; list[%s] = val", cnt, cnt, cnt)
+			// Repeated string/bytes — inline 1-byte LEN fast path. (a6n)
+			emitInlineStringBytesRepeated(w, st, cnt)
 		}
 	}
+}
+
+// emitInlineStringBytesScalar emits the singular string/bytes decode with the
+// 1-byte LEN fast path inlined. Falls back to `wire.decode_<st>` for lengths
+// >= 128. UTF-8 validation runs only for `string`, not `bytes`. (a6n)
+func emitInlineStringBytesScalar(w *writer, st, dst string) {
+	w.line("            local _lb = string_byte(buf, pos)")
+	w.line("            if _lb ~= nil and _lb < 0x80 then")
+	w.line("                local _np = pos + 1")
+	w.line("                local _epos = _np + _lb")
+	w.line("                if _epos - 1 > len then error(\"truncated LEN at offset \" .. pos, 0) end")
+	w.line("                local _s = buf:sub(_np, _epos - 1)")
+	if st == "string" {
+		w.line("                if utf8_len(_s) == nil then error(\"invalid UTF-8 in string field at offset \" .. pos, 0) end")
+	}
+	w.line("                %s = _s", dst)
+	w.line("                pos = _epos")
+	w.line("            else")
+	w.line("                local val")
+	w.line("                val, pos = wire.decode_%s(buf, pos)", st)
+	w.line("                %s = val", dst)
+	w.line("            end")
+}
+
+// emitInlineStringBytesRepeated mirrors emitInlineStringBytesScalar but
+// appends to the per-field list via the `_n_<f>` counter. (a6n)
+func emitInlineStringBytesRepeated(w *writer, st, cnt string) {
+	w.line("            local _lb = string_byte(buf, pos)")
+	w.line("            if _lb ~= nil and _lb < 0x80 then")
+	w.line("                local _np = pos + 1")
+	w.line("                local _epos = _np + _lb")
+	w.line("                if _epos - 1 > len then error(\"truncated LEN at offset \" .. pos, 0) end")
+	w.line("                local _s = buf:sub(_np, _epos - 1)")
+	if st == "string" {
+		w.line("                if utf8_len(_s) == nil then error(\"invalid UTF-8 in string field at offset \" .. pos, 0) end")
+	}
+	w.line("                %s = %s + 1; list[%s] = _s", cnt, cnt, cnt)
+	w.line("                pos = _epos")
+	w.line("            else")
+	w.line("                local val")
+	w.line("                val, pos = wire.decode_%s(buf, pos)", st)
+	w.line("                %s = %s + 1; list[%s] = val", cnt, cnt, cnt)
+	w.line("            end")
 }
 
 // ----------------------------------------------------------------------------
diff --git a/examples/expected/full/c_int64/c_int64_pb.lua b/examples/expected/full/c_int64/c_int64_pb.lua
index e07108a5e499d85305b8f09dafe644ac90a1cfe6..07526794fd6a8a744369ced61636464d733e83d8 100644
--- a/examples/expected/full/c_int64/c_int64_pb.lua
+++ b/examples/expected/full/c_int64/c_int64_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
diff --git a/examples/expected/full/c_nested/c_nested_pb.lua b/examples/expected/full/c_nested/c_nested_pb.lua
index 7e60060498ba4359343a2ad00ce187bcf60d5187..d3a43772e1cb868856d1b2507cb7c421a47d2400 100644
--- a/examples/expected/full/c_nested/c_nested_pb.lua
+++ b/examples/expected/full/c_nested/c_nested_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
diff --git a/examples/expected/full/c_repeated/c_repeated_pb.lua b/examples/expected/full/c_repeated/c_repeated_pb.lua
index 1702a9d0c7cf11d5e5f00b13de18f649e138602c..f3c3bc2d561083f1037e9e4da3ca376d5d03d655 100644
--- a/examples/expected/full/c_repeated/c_repeated_pb.lua
+++ b/examples/expected/full/c_repeated/c_repeated_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
@@ -175,9 +176,20 @@             local val
             val, pos = wire.decode_int32(buf, pos)
             result.v = val
         elseif id == 2 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.s = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.s = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.s = val
+            end
         else
             local _ebid = M.Inner_descriptor.extensions_by_id
             local _ext = _ebid and _ebid[id] or nil
@@ -715,15 +727,36 @@             end
         elseif id == 30 then
             local list = result.strings
             if list == nil then list = {}; result.strings = list end
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            _n_strings = _n_strings + 1; list[_n_strings] = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                _n_strings = _n_strings + 1; list[_n_strings] = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                _n_strings = _n_strings + 1; list[_n_strings] = val
+            end
         elseif id == 31 then
             local list = result.blobs
             if list == nil then list = {}; result.blobs = list end
-            local val
-            val, pos = wire.decode_bytes(buf, pos)
-            _n_blobs = _n_blobs + 1; list[_n_blobs] = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                _n_blobs = _n_blobs + 1; list[_n_blobs] = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_bytes(buf, pos)
+                _n_blobs = _n_blobs + 1; list[_n_blobs] = val
+            end
         elseif id == 40 then
             local list = result.messages
             if list == nil then list = {}; result.messages = list end
diff --git a/examples/expected/full/conformance/conformance_pb.lua b/examples/expected/full/conformance/conformance_pb.lua
index 46d4d2df62823a42525ba28e43a8dfa4771d340b..949df2b0759a7437c11423d7b0cc0fe63358b5fd 100644
--- a/examples/expected/full/conformance/conformance_pb.lua
+++ b/examples/expected/full/conformance/conformance_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
@@ -295,17 +296,50 @@         else
             id, wt, pos = wire.decode_tag(buf, pos)
         end
         if id == 1 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.name = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.name = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.name = val
+            end
         elseif id == 2 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.failure_message = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.failure_message = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.failure_message = val
+            end
         elseif id == 3 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.matched_name = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.matched_name = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.matched_name = val
+            end
         else
             local _ebid = M.TestStatus_descriptor.extensions_by_id
             local _ext = _ebid and _ebid[id] or nil
@@ -614,30 +648,73 @@         else
             id, wt, pos = wire.decode_tag(buf, pos)
         end
         if id == 1 then
-            local val
-            val, pos = wire.decode_bytes(buf, pos)
-            result.protobuf_payload = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                result.protobuf_payload = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_bytes(buf, pos)
+                result.protobuf_payload = val
+            end
             result.json_payload = nil
             result.jspb_payload = nil
             result.text_payload = nil
         elseif id == 2 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.json_payload = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.json_payload = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.json_payload = val
+            end
             result.protobuf_payload = nil
             result.jspb_payload = nil
             result.text_payload = nil
         elseif id == 7 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.jspb_payload = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.jspb_payload = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.jspb_payload = val
+            end
             result.protobuf_payload = nil
             result.json_payload = nil
             result.text_payload = nil
         elseif id == 8 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.text_payload = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.text_payload = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.text_payload = val
+            end
             result.protobuf_payload = nil
             result.json_payload = nil
             result.jspb_payload = nil
@@ -646,9 +723,20 @@             local u
             u, pos = wire.decode_varint(buf, pos)
             result.requested_output_format = wire.varint_to_int32(u)
         elseif id == 4 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.message_type = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.message_type = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.message_type = val
+            end
         elseif id == 5 then
             local u
             u, pos = wire.decode_varint(buf, pos)
@@ -872,9 +960,20 @@         else
             id, wt, pos = wire.decode_tag(buf, pos)
         end
         if id == 1 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.parse_error = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.parse_error = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.parse_error = val
+            end
             result.serialize_error = nil
             result.timeout_error = nil
             result.runtime_error = nil
@@ -884,9 +983,20 @@             result.skipped = nil
             result.jspb_payload = nil
             result.text_payload = nil
         elseif id == 6 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.serialize_error = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.serialize_error = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.serialize_error = val
+            end
             result.parse_error = nil
             result.timeout_error = nil
             result.runtime_error = nil
@@ -896,9 +1006,20 @@             result.skipped = nil
             result.jspb_payload = nil
             result.text_payload = nil
         elseif id == 9 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.timeout_error = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.timeout_error = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.timeout_error = val
+            end
             result.parse_error = nil
             result.serialize_error = nil
             result.runtime_error = nil
@@ -908,9 +1029,20 @@             result.skipped = nil
             result.jspb_payload = nil
             result.text_payload = nil
         elseif id == 2 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.runtime_error = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.runtime_error = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.runtime_error = val
+            end
             result.parse_error = nil
             result.serialize_error = nil
             result.timeout_error = nil
@@ -920,9 +1052,19 @@             result.skipped = nil
             result.jspb_payload = nil
             result.text_payload = nil
         elseif id == 3 then
-            local val
-            val, pos = wire.decode_bytes(buf, pos)
-            result.protobuf_payload = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                result.protobuf_payload = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_bytes(buf, pos)
+                result.protobuf_payload = val
+            end
             result.parse_error = nil
             result.serialize_error = nil
             result.timeout_error = nil
@@ -932,9 +1074,20 @@             result.skipped = nil
             result.jspb_payload = nil
             result.text_payload = nil
         elseif id == 4 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.json_payload = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.json_payload = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.json_payload = val
+            end
             result.parse_error = nil
             result.serialize_error = nil
             result.timeout_error = nil
@@ -944,9 +1097,20 @@             result.skipped = nil
             result.jspb_payload = nil
             result.text_payload = nil
         elseif id == 5 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.skipped = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.skipped = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.skipped = val
+            end
             result.parse_error = nil
             result.serialize_error = nil
             result.timeout_error = nil
@@ -956,9 +1120,20 @@             result.json_payload = nil
             result.jspb_payload = nil
             result.text_payload = nil
         elseif id == 7 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.jspb_payload = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.jspb_payload = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.jspb_payload = val
+            end
             result.parse_error = nil
             result.serialize_error = nil
             result.timeout_error = nil
@@ -968,9 +1143,20 @@             result.json_payload = nil
             result.skipped = nil
             result.text_payload = nil
         elseif id == 8 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.text_payload = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.text_payload = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.text_payload = val
+            end
             result.parse_error = nil
             result.serialize_error = nil
             result.timeout_error = nil
diff --git a/examples/expected/full/hello/hello_pb.lua b/examples/expected/full/hello/hello_pb.lua
index 09972e35f3ce51c623b32223b21a51e713ed7876..22688ac6544da3cf842fbcd23d06e7aca403775b 100644
--- a/examples/expected/full/hello/hello_pb.lua
+++ b/examples/expected/full/hello/hello_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
@@ -315,9 +316,20 @@             local val
             val, pos = wire.decode_int32(buf, pos)
             result.id = val
         elseif id == 2 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.text = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.text = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.text = val
+            end
             result.code = nil
             result.details = nil
         elseif id == 3 then
@@ -437,9 +449,20 @@         else
             id, wt, pos = wire.decode_tag(buf, pos)
         end
         if id == 1 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.name = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.name = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.name = val
+            end
         else
             local _ebid = M.HelloRequest_descriptor.extensions_by_id
             local _ext = _ebid and _ebid[id] or nil
@@ -540,9 +563,20 @@         else
             id, wt, pos = wire.decode_tag(buf, pos)
         end
         if id == 1 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.greeting = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.greeting = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.greeting = val
+            end
         else
             local _ebid = M.HelloReply_descriptor.extensions_by_id
             local _ext = _ebid and _ebid[id] or nil
@@ -786,9 +820,20 @@         else
             id, wt, pos = wire.decode_tag(buf, pos)
         end
         if id == 1 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.title = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.title = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.title = val
+            end
         elseif id == 2 then
             local payload
             payload, pos = wire.decode_len(buf, pos)
@@ -963,21 +1008,54 @@         else
             id, wt, pos = wire.decode_tag(buf, pos)
         end
         if id == 1 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.street = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.street = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.street = val
+            end
         elseif id == 2 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.city = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.city = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.city = val
+            end
         elseif id == 3 then
             local val
             val, pos = wire.decode_int32(buf, pos)
             result.zip = val
         elseif id == 4 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.apartment = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.apartment = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.apartment = val
+            end
         else
             local _ebid = M.Address_descriptor.extensions_by_id
             local _ext = _ebid and _ebid[id] or nil
@@ -1272,9 +1350,20 @@         else
             id, wt, pos = wire.decode_tag(buf, pos)
         end
         if id == 1 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.name = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.name = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.name = val
+            end
         elseif id == 2 then
             local val
             val, pos = wire.decode_int32(buf, pos)
@@ -1282,9 +1371,20 @@             result.age = val
         elseif id == 3 then
             local list = result.emails
             if list == nil then list = {}; result.emails = list end
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            _n_emails = _n_emails + 1; list[_n_emails] = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                _n_emails = _n_emails + 1; list[_n_emails] = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                _n_emails = _n_emails + 1; list[_n_emails] = val
+            end
         elseif id == 4 then
             local u
             u, pos = wire.decode_varint(buf, pos)
@@ -1322,9 +1422,19 @@                 val, pos = wire.decode_int32(buf, pos)
                 _n_lucky_numbers = _n_lucky_numbers + 1; list[_n_lucky_numbers] = val
             end
         elseif id == 8 then
-            local val
-            val, pos = wire.decode_bytes(buf, pos)
-            result.avatar = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                result.avatar = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_bytes(buf, pos)
+                result.avatar = val
+            end
         elseif id == 9 then
             local val
             val, pos = wire.decode_fixed64(buf, pos)
diff --git a/examples/expected/full/proto2_basic/proto2_basic_pb.lua b/examples/expected/full/proto2_basic/proto2_basic_pb.lua
index de656e18247b72d6fc924179769f7e68829e8ecc..6f657eea50f256507e8efbc1cbb9c2abc31db942 100644
--- a/examples/expected/full/proto2_basic/proto2_basic_pb.lua
+++ b/examples/expected/full/proto2_basic/proto2_basic_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
@@ -372,9 +373,20 @@             local val
             val, pos = wire.decode_int32(buf, pos)
             result.i = val
         elseif id == 2 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.s = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.s = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.s = val
+            end
         elseif id == 3 then
             local val
             val, pos = wire.decode_bool(buf, pos)
@@ -396,9 +408,19 @@             local val
             val, pos = wire.decode_uint64(buf, pos)
             result.u64 = val
         elseif id == 8 then
-            local val
-            val, pos = wire.decode_bytes(buf, pos)
-            result.by = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                result.by = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_bytes(buf, pos)
+                result.by = val
+            end
         elseif id == 9 then
             local u
             u, pos = wire.decode_varint(buf, pos)
@@ -1121,9 +1143,20 @@             local val
             val, pos = wire.decode_int32(buf, pos)
             result.a = val
         elseif id == 3 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.s = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.s = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.s = val
+            end
         else
             local _ebid = M.WithGroup_SingleGroup_descriptor.extensions_by_id
             local _ext = _ebid and _ebid[id] or nil
@@ -1408,9 +1441,20 @@             local val
             val, pos = wire.decode_int32(buf, pos)
             result.id = val
         elseif id == 2 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.name = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.name = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.name = val
+            end
         elseif id == 3 then
             local val
             val, pos = wire.decode_int32(buf, pos)
@@ -1435,9 +1479,20 @@             end
         elseif id == 5 then
             local list = result.tags
             if list == nil then list = {}; result.tags = list end
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            _n_tags = _n_tags + 1; list[_n_tags] = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                _n_tags = _n_tags + 1; list[_n_tags] = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                _n_tags = _n_tags + 1; list[_n_tags] = val
+            end
         elseif id == 6 then
             local payload
             payload, pos = wire.decode_len(buf, pos)
@@ -1700,9 +1755,20 @@         else
             id, wt, pos = wire.decode_tag(buf, pos)
         end
         if id == 1 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.key = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.key = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.key = val
+            end
         elseif id == 2 then
             local val
             val, pos = wire.decode_int32(buf, pos)
diff --git a/examples/expected/full/protobuf_test_messages/proto2/test_messages_proto2_pb.lua b/examples/expected/full/protobuf_test_messages/proto2/test_messages_proto2_pb.lua
index 571731cb6693ec45932ce95aa14d2f1bf566bc7b..698bb690b2589109569ed57c0d58cf07d6d8f09f 100644
--- a/examples/expected/full/protobuf_test_messages/proto2/test_messages_proto2_pb.lua
+++ b/examples/expected/full/protobuf_test_messages/proto2/test_messages_proto2_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
@@ -2737,13 +2738,34 @@             local val
             val, pos = wire.decode_bool(buf, pos)
             result.optional_bool = val
         elseif id == 14 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.optional_string = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.optional_string = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.optional_string = val
+            end
         elseif id == 15 then
-            local val
-            val, pos = wire.decode_bytes(buf, pos)
-            result.optional_bytes = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                result.optional_bytes = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_bytes(buf, pos)
+                result.optional_bytes = val
+            end
         elseif id == 18 then
             local payload
             payload, pos = wire.decode_len(buf, pos)
@@ -2771,13 +2793,35 @@             local u
             u, pos = wire.decode_varint(buf, pos)
             result.optional_foreign_enum = wire.varint_to_int32(u)
         elseif id == 24 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.optional_string_piece = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.optional_string_piece = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.optional_string_piece = val
+            end
         elseif id == 25 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.optional_cord = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.optional_cord = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.optional_cord = val
+            end
         elseif id == 27 then
             local payload
             payload, pos = wire.decode_len(buf, pos)
@@ -3011,15 +3055,36 @@             end
         elseif id == 44 then
             local list = result.repeated_string
             if list == nil then list = {}; result.repeated_string = list end
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            _n_repeated_string = _n_repeated_string + 1; list[_n_repeated_string] = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                _n_repeated_string = _n_repeated_string + 1; list[_n_repeated_string] = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                _n_repeated_string = _n_repeated_string + 1; list[_n_repeated_string] = val
+            end
         elseif id == 45 then
             local list = result.repeated_bytes
             if list == nil then list = {}; result.repeated_bytes = list end
-            local val
-            val, pos = wire.decode_bytes(buf, pos)
-            _n_repeated_bytes = _n_repeated_bytes + 1; list[_n_repeated_bytes] = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                _n_repeated_bytes = _n_repeated_bytes + 1; list[_n_repeated_bytes] = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_bytes(buf, pos)
+                _n_repeated_bytes = _n_repeated_bytes + 1; list[_n_repeated_bytes] = val
+            end
         elseif id == 48 then
             local list = result.repeated_nested_message
             if list == nil then list = {}; result.repeated_nested_message = list end
@@ -3069,15 +3134,37 @@             end
         elseif id == 54 then
             local list = result.repeated_string_piece
             if list == nil then list = {}; result.repeated_string_piece = list end
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            _n_repeated_string_piece = _n_repeated_string_piece + 1; list[_n_repeated_string_piece] = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                _n_repeated_string_piece = _n_repeated_string_piece + 1; list[_n_repeated_string_piece] = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                _n_repeated_string_piece = _n_repeated_string_piece + 1; list[_n_repeated_string_piece] = val
+            end
         elseif id == 55 then
             local list = result.repeated_cord
             if list == nil then list = {}; result.repeated_cord = list end
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            _n_repeated_cord = _n_repeated_cord + 1; list[_n_repeated_cord] = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                _n_repeated_cord = _n_repeated_cord + 1; list[_n_repeated_cord] = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                _n_repeated_cord = _n_repeated_cord + 1; list[_n_repeated_cord] = val
+            end
         elseif id == 75 then
             local list = result.packed_int32
             if list == nil then list = {}; result.packed_int32 = list end
@@ -4008,9 +4095,20 @@             result.oneof_float = nil
             result.oneof_double = nil
             result.oneof_enum = nil
         elseif id == 113 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.oneof_string = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.oneof_string = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.oneof_string = val
+            end
             result.oneof_uint32 = nil
             result.oneof_nested_message = nil
             result.oneof_bytes = nil
@@ -4020,9 +4118,19 @@             result.oneof_float = nil
             result.oneof_double = nil
             result.oneof_enum = nil
         elseif id == 114 then
-            local val
-            val, pos = wire.decode_bytes(buf, pos)
-            result.oneof_bytes = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                result.oneof_bytes = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_bytes(buf, pos)
+                result.oneof_bytes = val
+            end
             result.oneof_uint32 = nil
             result.oneof_nested_message = nil
             result.oneof_string = nil
@@ -4162,13 +4270,34 @@             local val
             val, pos = wire.decode_bool(buf, pos)
             result.default_bool = val
         elseif id == 254 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.default_string = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.default_string = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.default_string = val
+            end
         elseif id == 255 then
-            local val
-            val, pos = wire.decode_bytes(buf, pos)
-            result.default_bytes = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                result.default_bytes = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_bytes(buf, pos)
+                result.default_bytes = val
+            end
         elseif id == 401 then
             local val
             val, pos = wire.decode_int32(buf, pos)
@@ -5254,9 +5383,20 @@             local val
             val, pos = wire.decode_int32(buf, pos)
             result.optional_int32 = val
         elseif id == 1002 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.optional_string = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.optional_string = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.optional_string = val
+            end
         elseif id == 1003 then
             local payload
             payload, pos = wire.decode_len(buf, pos)
@@ -5699,9 +5839,20 @@         else
             id, wt, pos = wire.decode_tag(buf, pos)
         end
         if id == 1 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.data = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.data = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.data = val
+            end
         else
             local _ebid = M.OneStringProto2_descriptor.extensions_by_id
             local _ext = _ebid and _ebid[id] or nil
@@ -5834,15 +5985,37 @@             local val
             val, pos = wire.decode_int32(buf, pos)
             result.inline = val
         elseif id == 2 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.concept = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.concept = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.concept = val
+            end
         elseif id == 3 then
             local list = result.requires
             if list == nil then list = {}; result.requires = list end
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            _n_requires = _n_requires + 1; list[_n_requires] = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                _n_requires = _n_requires + 1; list[_n_requires] = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                _n_requires = _n_requires + 1; list[_n_requires] = val
+            end
         else
             local _ebid = M.ProtoWithKeywords_descriptor.extensions_by_id
             local _ext = _ebid and _ebid[id] or nil
@@ -6350,13 +6523,34 @@             local val
             val, pos = wire.decode_bool(buf, pos)
             result.required_bool = val
         elseif id == 14 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.required_string = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.required_string = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.required_string = val
+            end
         elseif id == 15 then
-            local val
-            val, pos = wire.decode_bytes(buf, pos)
-            result.required_bytes = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                result.required_bytes = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_bytes(buf, pos)
+                result.required_bytes = val
+            end
         elseif id == 18 then
             local payload
             payload, pos = wire.decode_len(buf, pos)
@@ -6384,13 +6578,35 @@             local u
             u, pos = wire.decode_varint(buf, pos)
             result.required_foreign_enum = wire.varint_to_int32(u)
         elseif id == 24 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.required_string_piece = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.required_string_piece = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.required_string_piece = val
+            end
         elseif id == 25 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.required_cord = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.required_cord = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.required_cord = val
+            end
         elseif id == 27 then
             local payload
             payload, pos = wire.decode_len(buf, pos)
@@ -6471,13 +6687,34 @@             local val
             val, pos = wire.decode_bool(buf, pos)
             result.default_bool = val
         elseif id == 254 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.default_string = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.default_string = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.default_string = val
+            end
         elseif id == 255 then
-            local val
-            val, pos = wire.decode_bytes(buf, pos)
-            result.default_bytes = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                result.default_bytes = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_bytes(buf, pos)
+                result.default_bytes = val
+            end
         else
             local _ebid = M.TestAllRequiredTypesProto2_descriptor.extensions_by_id
             local _ext = _ebid and _ebid[id] or nil
diff --git a/examples/expected/full/protobuf_test_messages/proto3/test_messages_proto3_pb.lua b/examples/expected/full/protobuf_test_messages/proto3/test_messages_proto3_pb.lua
index fea5a71521f3081af319159db4f8be60f9f770cd..4128053ce1bf6e97ce51982ccdfcf56fd4a0c2a5 100644
--- a/examples/expected/full/protobuf_test_messages/proto3/test_messages_proto3_pb.lua
+++ b/examples/expected/full/protobuf_test_messages/proto3/test_messages_proto3_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
@@ -2908,13 +2909,34 @@             local val
             val, pos = wire.decode_bool(buf, pos)
             result.optional_bool = val
         elseif id == 14 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.optional_string = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.optional_string = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.optional_string = val
+            end
         elseif id == 15 then
-            local val
-            val, pos = wire.decode_bytes(buf, pos)
-            result.optional_bytes = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                result.optional_bytes = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_bytes(buf, pos)
+                result.optional_bytes = val
+            end
         elseif id == 18 then
             local payload
             payload, pos = wire.decode_len(buf, pos)
@@ -2946,13 +2968,35 @@             local u
             u, pos = wire.decode_varint(buf, pos)
             result.optional_aliased_enum = wire.varint_to_int32(u)
         elseif id == 24 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.optional_string_piece = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.optional_string_piece = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.optional_string_piece = val
+            end
         elseif id == 25 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.optional_cord = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.optional_cord = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.optional_cord = val
+            end
         elseif id == 27 then
             local payload
             payload, pos = wire.decode_len(buf, pos)
@@ -3186,15 +3230,36 @@             end
         elseif id == 44 then
             local list = result.repeated_string
             if list == nil then list = {}; result.repeated_string = list end
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            _n_repeated_string = _n_repeated_string + 1; list[_n_repeated_string] = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                _n_repeated_string = _n_repeated_string + 1; list[_n_repeated_string] = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                _n_repeated_string = _n_repeated_string + 1; list[_n_repeated_string] = val
+            end
         elseif id == 45 then
             local list = result.repeated_bytes
             if list == nil then list = {}; result.repeated_bytes = list end
-            local val
-            val, pos = wire.decode_bytes(buf, pos)
-            _n_repeated_bytes = _n_repeated_bytes + 1; list[_n_repeated_bytes] = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                _n_repeated_bytes = _n_repeated_bytes + 1; list[_n_repeated_bytes] = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_bytes(buf, pos)
+                _n_repeated_bytes = _n_repeated_bytes + 1; list[_n_repeated_bytes] = val
+            end
         elseif id == 48 then
             local list = result.repeated_nested_message
             if list == nil then list = {}; result.repeated_nested_message = list end
@@ -3244,15 +3309,37 @@             end
         elseif id == 54 then
             local list = result.repeated_string_piece
             if list == nil then list = {}; result.repeated_string_piece = list end
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            _n_repeated_string_piece = _n_repeated_string_piece + 1; list[_n_repeated_string_piece] = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                _n_repeated_string_piece = _n_repeated_string_piece + 1; list[_n_repeated_string_piece] = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                _n_repeated_string_piece = _n_repeated_string_piece + 1; list[_n_repeated_string_piece] = val
+            end
         elseif id == 55 then
             local list = result.repeated_cord
             if list == nil then list = {}; result.repeated_cord = list end
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            _n_repeated_cord = _n_repeated_cord + 1; list[_n_repeated_cord] = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                _n_repeated_cord = _n_repeated_cord + 1; list[_n_repeated_cord] = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                _n_repeated_cord = _n_repeated_cord + 1; list[_n_repeated_cord] = val
+            end
         elseif id == 75 then
             local list = result.packed_int32
             if list == nil then list = {}; result.packed_int32 = list end
@@ -4145,9 +4232,20 @@             result.oneof_double = nil
             result.oneof_enum = nil
             result.oneof_null_value = nil
         elseif id == 113 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.oneof_string = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.oneof_string = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.oneof_string = val
+            end
             result.oneof_uint32 = nil
             result.oneof_nested_message = nil
             result.oneof_bytes = nil
@@ -4158,9 +4256,19 @@             result.oneof_double = nil
             result.oneof_enum = nil
             result.oneof_null_value = nil
         elseif id == 114 then
-            local val
-            val, pos = wire.decode_bytes(buf, pos)
-            result.oneof_bytes = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                result.oneof_bytes = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_bytes(buf, pos)
+                result.oneof_bytes = val
+            end
             result.oneof_uint32 = nil
             result.oneof_nested_message = nil
             result.oneof_string = nil
diff --git a/examples/expected/full/quickstart/quickstart_pb.lua b/examples/expected/full/quickstart/quickstart_pb.lua
index 11cf3fb2623635cbb2c1468a6919e491a75060fc..cdb0ce452f3df7d360f09366df54f61b4af0ddb7 100644
--- a/examples/expected/full/quickstart/quickstart_pb.lua
+++ b/examples/expected/full/quickstart/quickstart_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
@@ -166,9 +167,20 @@             local val
             val, pos = wire.decode_int32(buf, pos)
             result.id = val
         elseif id == 2 then
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            result.name = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                result.name = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                result.name = val
+            end
         elseif id == 3 then
             local u
             u, pos = wire.decode_varint(buf, pos)
@@ -176,9 +188,20 @@             result.role = wire.varint_to_int32(u)
         elseif id == 4 then
             local list = result.emails
             if list == nil then list = {}; result.emails = list end
-            local val
-            val, pos = wire.decode_string(buf, pos)
-            _n_emails = _n_emails + 1; list[_n_emails] = val
+            local _lb = string_byte(buf, pos)
+            if _lb ~= nil and _lb < 0x80 then
+                local _np = pos + 1
+                local _epos = _np + _lb
+                if _epos - 1 > len then error("truncated LEN at offset " .. pos, 0) end
+                local _s = buf:sub(_np, _epos - 1)
+                if utf8_len(_s) == nil then error("invalid UTF-8 in string field at offset " .. pos, 0) end
+                _n_emails = _n_emails + 1; list[_n_emails] = _s
+                pos = _epos
+            else
+                local val
+                val, pos = wire.decode_string(buf, pos)
+                _n_emails = _n_emails + 1; list[_n_emails] = val
+            end
         else
             local _ebid = M.User_descriptor.extensions_by_id
             local _ext = _ebid and _ebid[id] or nil
diff --git a/examples/expected/runtime/c_int64/c_int64_pb.lua b/examples/expected/runtime/c_int64/c_int64_pb.lua
index df51cb81c349d1aecdcb8a65baec7067d9ed0d2f..23441b30318c48dda0e947dbd757e9c34ecbdf74 100644
--- a/examples/expected/runtime/c_int64/c_int64_pb.lua
+++ b/examples/expected/runtime/c_int64/c_int64_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
diff --git a/examples/expected/runtime/c_nested/c_nested_pb.lua b/examples/expected/runtime/c_nested/c_nested_pb.lua
index 17bece7ae171c163c06cf38c278a1ca1e1b57491..707cd31b54e5389f88c493ebf98f17fae792dbe8 100644
--- a/examples/expected/runtime/c_nested/c_nested_pb.lua
+++ b/examples/expected/runtime/c_nested/c_nested_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
diff --git a/examples/expected/runtime/c_repeated/c_repeated_pb.lua b/examples/expected/runtime/c_repeated/c_repeated_pb.lua
index 693680e1fba9caacc0eb92024ca135288429eb63..1a9339ff85d51038c7ad000c85e39c2e10093f65 100644
--- a/examples/expected/runtime/c_repeated/c_repeated_pb.lua
+++ b/examples/expected/runtime/c_repeated/c_repeated_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
diff --git a/examples/expected/runtime/conformance/conformance_pb.lua b/examples/expected/runtime/conformance/conformance_pb.lua
index 7c79ece1019f58b0512a24d8b77eb7ec2b310e56..0db005fb1157ae0daef0babf3ae40a0daa92399d 100644
--- a/examples/expected/runtime/conformance/conformance_pb.lua
+++ b/examples/expected/runtime/conformance/conformance_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
diff --git a/examples/expected/runtime/hello/hello_pb.lua b/examples/expected/runtime/hello/hello_pb.lua
index 41c78290c1d25150f86b354646fe52793a1092be..f74e7a72b36e274f7bd06bfbc8e70b842f37b36a 100644
--- a/examples/expected/runtime/hello/hello_pb.lua
+++ b/examples/expected/runtime/hello/hello_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
diff --git a/examples/expected/runtime/proto2_basic/proto2_basic_pb.lua b/examples/expected/runtime/proto2_basic/proto2_basic_pb.lua
index 82672b26e02947fcb096395eb5063d414afedf91..a6a904ff4b61e9ff24189c73282648ac8f58121e 100644
--- a/examples/expected/runtime/proto2_basic/proto2_basic_pb.lua
+++ b/examples/expected/runtime/proto2_basic/proto2_basic_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
diff --git a/examples/expected/runtime/protobuf_test_messages/proto2/test_messages_proto2_pb.lua b/examples/expected/runtime/protobuf_test_messages/proto2/test_messages_proto2_pb.lua
index 53c3542fadf859a8658c1424bc32c7a9b377fd98..95af5739182e6fb4e9c3362e4c9d88cbf9666ef8 100644
--- a/examples/expected/runtime/protobuf_test_messages/proto2/test_messages_proto2_pb.lua
+++ b/examples/expected/runtime/protobuf_test_messages/proto2/test_messages_proto2_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
diff --git a/examples/expected/runtime/protobuf_test_messages/proto3/test_messages_proto3_pb.lua b/examples/expected/runtime/protobuf_test_messages/proto3/test_messages_proto3_pb.lua
index ff1d5a42ef101cb33bf12cae68f9571e3478c339..9878619f254b079d42575d23717535a10013c96e 100644
--- a/examples/expected/runtime/protobuf_test_messages/proto3/test_messages_proto3_pb.lua
+++ b/examples/expected/runtime/protobuf_test_messages/proto3/test_messages_proto3_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift
 
diff --git a/examples/expected/runtime/quickstart/quickstart_pb.lua b/examples/expected/runtime/quickstart/quickstart_pb.lua
index b416929f581afa6f713ce20c015e4d103a64dba3..e1ff77f3037f13fe9ce6a5a3f26bd54b448500ff 100644
--- a/examples/expected/runtime/quickstart/quickstart_pb.lua
+++ b/examples/expected/runtime/quickstart/quickstart_pb.lua
@@ -6,6 +6,7 @@
 local pb = require("pb")
 local wire = pb.wire
 local string_byte = string.byte
+local utf8_len = require('utf8').len
 local band = bit.band
 local rshift = bit.rshift