diff --git a/src/mnode_proto_test1.cc b/src/mnode_proto_test1.cc
index 662e018..f10f972 100644
--- a/src/mnode_proto_test1.cc
+++ b/src/mnode_proto_test1.cc
@@ -25,7 +25,7 @@ void requester(nng_socket socket, unsigned id)
         auto reqMsg = nng::make_message(ping.SerializeAsString());
         if (int rc = nng_sendmsg(socket, reqMsg.release(), 0))
         {
-            nng::mesy_nng_error("nng_sendmsg", rc);
+            nng::mesy_nng_error("req: nng_sendmsg", rc);
             if (rc != NNG_ETIMEDOUT)
                 return;
             continue;
@@ -34,7 +34,7 @@ void requester(nng_socket socket, unsigned id)
         auto [repMsg, rc] = nng::receive_message(socket);
         if (rc)
         {
-            nng::mesy_nng_error("nng_recvmsg", rc);
+            nng::mesy_nng_error("requester: nng_recvmsg", rc);
             if (rc != NNG_ETIMEDOUT)
                 return;
             continue;
@@ -61,7 +61,7 @@ void responder(nng_socket socket, unsigned id)
         auto [reqMsg, rc] = nng::receive_message(socket);
         if (rc)
         {
-            nng::mesy_nng_error("nng_recvmsg", rc);
+            nng::mesy_nng_error("responder: nng_recvmsg", rc);
             if (rc != NNG_ETIMEDOUT)
                 return;
             continue;
@@ -74,7 +74,7 @@ void responder(nng_socket socket, unsigned id)
         auto repMsg = nng::make_message(pong.SerializeAsString());
         if (int rc = nng_sendmsg(socket, repMsg.release(), 0))
         {
-            nng::mesy_nng_error("nng_sendmsg", rc);
+            nng::mesy_nng_error("responder: nng_sendmsg", rc);
             if (rc != NNG_ETIMEDOUT)
                 return;
             continue;