diff --git a/Transceiver52M/Transceiver.cpp b/Transceiver52M/Transceiver.cpp
index cff0b3a..1e80018 100644
--- a/Transceiver52M/Transceiver.cpp
+++ b/Transceiver52M/Transceiver.cpp
@@ -759,6 +759,7 @@
   }
   else {
     LOG(WARNING) << "bogus command " << command << " on control interface.";
+    sprintf(response,"RSP ERR 1");
   }
 
   mCtrlSockets[chan]->write(response, strlen(response) + 1);