diff --git a/gprofng/src/ipc.cc b/gprofng/src/ipc.cc
index 3e706dbc9d0..feda1f8eb08 100644
--- a/gprofng/src/ipc.cc
+++ b/gprofng/src/ipc.cc
@@ -2534,8 +2534,10 @@ ipc_doWork (void *arg)
     }
   else
     {
-      ipc_log ("Unrecognized input cmd \"%s\"; Aborting.\n", inp);
-      return 1;
+      char *s = dbe_sprintf ("Unrecognized request: \"%s\"", inp);
+      ipc_log ("%s\n", s);
+      writeError (s, req);
+      free (s);
     }
   ipc_log ("  processing IPC command %s complete\n", inp);
   free (inp);
diff --git a/gprofng/src/ipcio.cc b/gprofng/src/ipcio.cc
index 8ff16d5a8e2..c20a22f9b60 100644
--- a/gprofng/src/ipcio.cc
+++ b/gprofng/src/ipcio.cc
@@ -776,6 +776,16 @@ writeString (const char *s, IPCrequest* req)
 			   RESPONSE_TYPE_COMPLETE, RESPONSE_STATUS_SUCCESS, OUTS);
 }
 
+void
+writeError (const char *s, IPCrequest* req)
+{
+  IPCresponse *OUTS = responseBufferPool->getNewResponse (BUFFER_SIZE_LARGE);
+  OUTS->sendByte (L_STRING);
+  OUTS->sendSVal (s);
+  writeResponseWithHeader (req->getRequestID (), req->getChannelID (),
+			   RESPONSE_TYPE_COMPLETE, RESPONSE_STATUS_ERROR, OUTS);
+}
+
 void
 writeObject (DbeObj obj, IPCrequest* req)
 {
diff --git a/gprofng/src/ipcio.h b/gprofng/src/ipcio.h
index 23c35fc33dd..7cef74311b8 100644
--- a/gprofng/src/ipcio.h
+++ b/gprofng/src/ipcio.h
@@ -40,6 +40,7 @@ typedef char *String;
 #define RESPONSE_STATUS_SUCCESS     1
 #define RESPONSE_STATUS_FAILURE     2
 #define RESPONSE_STATUS_CANCELLED   3
+#define RESPONSE_STATUS_ERROR       4
 
 #define RESPONSE_TYPE_ACK           0
 #define RESPONSE_TYPE_PROGRESS      1
@@ -60,7 +61,8 @@ enum IPCrequestStatus
   IN_PROGRESS,
   COMPLETED,
   CANCELLED_DEFAULT,
-  CANCELLED_IMMEDIATE
+  CANCELLED_IMMEDIATE,
+  UNDEFINED_REGUEST
 };
 
 enum IPCTraceLevel
@@ -151,6 +153,7 @@ String readString (IPCrequest*);
 void readRequestHeader ();
 
 // write to the wire
+void writeError (const char *, IPCrequest*);
 void writeString (const char *, IPCrequest*);
 void writeBoolean (bool, IPCrequest*);
 void writeInt (int, IPCrequest*);