diff --git a/source/common/protobuf/utility.cc b/source/common/protobuf/utility.cc
index 36270ec5611b9..c944515c31211 100644
--- a/source/common/protobuf/utility.cc
+++ b/source/common/protobuf/utility.cc
@@ -291,8 +291,9 @@ std::string MessageUtil::CodeEnumToString(ProtobufUtil::error::Code code) {
     return "UNAVAILABLE";
   case ProtobufUtil::error::DATA_LOSS:
     return "DATA_LOSS";
+  default:
+    return "";
   }
-  return "";
 }
 
 bool ValueUtil::equal(const ProtobufWkt::Value& v1, const ProtobufWkt::Value& v2) {