diff --git a/sql/protocol.cc b/sql/protocol.cc
index adb925a8cd4..da9f5712e3a 100644
--- a/sql/protocol.cc
+++ b/sql/protocol.cc
@@ -40,9 +40,9 @@ bool Protocol::net_store_data(const char *from, uint length)
   return 0;
 }
 
-bool Protocol::convert_str(const char *from, uint length)
+inline bool Protocol::convert_str(const char *from, uint length)
 {
-  convert->store(packet, from, length);
+  return convert->store(packet, from, length);
 }
 #endif