diff --git a/src/google/protobuf/util/json_format_proto3.proto b/src/google/protobuf/util/json_format_proto3.proto
index dee5e0412f09..565ad887b436 100644
--- a/src/google/protobuf/util/json_format_proto3.proto
+++ b/src/google/protobuf/util/json_format_proto3.proto
@@ -184,6 +184,9 @@ message TestEvilJson {
   int32 quotes = 3 [json_name = "unbalanced\"quotes"];
   int32 script_and_quotes = 4
       [json_name = "\"<script>alert('hello!);</script>"];
+  int32 empty_string = 5 [json_name = ""];
+  int32 backslash = 6 [json_name = "\\"];
+  int32 low_codepoint = 7 [json_name = "\1"];
 }
 
 message TestExtensions {