diff --git a/src/google/protobuf/generated_enum_reflection.h b/src/google/protobuf/generated_enum_reflection.h
index b0ac1b041ae78..b4bb0d09feb2d 100644
--- a/src/google/protobuf/generated_enum_reflection.h
+++ b/src/google/protobuf/generated_enum_reflection.h
@@ -1,3 +1,7 @@
+#ifndef GOOGLE_PROTOBUF_GENERATED_ENUM_REFLECTION_H__
+#define GOOGLE_PROTOBUF_GENERATED_ENUM_REFLECTION_H__
+
+#endif  // GOOGLE_PROTOBUF_GENERATED_ENUM_REFLECTION_H__
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 //