--- a/src/core/lib/transport/metadata_batch.cc	(index)
+++ b/src/core/lib/transport/metadata_batch.cc	(working tree)
@@ -26,6 +26,14 @@
 
 #include "src/core/lib/transport/timeout_encoding.h"
 
+template<>
+void Out<grpc_status_code>(IOutputStream& os, grpc_status_code t) {
+    // We use ::ToString for convertation of status code to string,
+    // but it requries definition of the void Out<T>
+    // see util/stream/output.h for details
+    os << static_cast<int>(t);
+}
+
 namespace grpc_core {
 namespace metadata_detail {