diff --git a/database/sq.go b/database/sq.go
index 3fbe5ab9d5da06719e9135f18de8a3cec5adc60a..cda4614933bbb5f175ae977a0597e2a36647afd2 100644
--- a/database/sq.go
+++ b/database/sq.go
@@ -134,7 +134,12 @@ 				update = update.Set(WithAlias(m.Alias(), f.SQL),
 					reflect.Indirect(rv).Interface())
 			}
 		} else {
-			panic(fmt.Errorf("TODO"))
+			if !rv.IsValid() {
+				panic(fmt.Errorf("Invariant violated (unsetting non-nullable field)"))
+			} else {
+				pv.Set(rv)
+				update = update.Set(WithAlias(m.Alias(), f.SQL), rv.Interface())
+			}
 		}
 	}