diff --git a/internal/server/rpc/gateway_rpc_servlet_handlers.go b/internal/server/rpc/gateway_rpc_servlet_handlers.go
index a540b51..f6985a3 100644
--- a/internal/server/rpc/gateway_rpc_servlet_handlers.go
+++ b/internal/server/rpc/gateway_rpc_servlet_handlers.go
@@ -38,8 +38,9 @@ func (sh *GatewayRPCServletHandlers) Invoke(servletCTX rpc.ServletContext, reque
 
 	md := servletCTX.GetAttribute(oogw.GRPCMetadataKey)
 	if nil == md {
+		clientType := servletCTX.GetAttribute(oogw.ClientTypeKey).(oogw.ClientType)
 		md = metadata.Pairs(
-			oogw.GRPCClientTypeKey, servletCTX.GetAttribute(oogw.ClientTypeKey).(string),
+			oogw.GRPCClientTypeKey, clientType.String(),
 			oogw.GRPCSessionIDKey, servletCTX.GetAttribute(oogw.SocketIDKey).(string),
 			oogw.GRPCTargetIDKey, servletCTX.GetAttribute(oogw.TargetIDKey).(string))