diff --git a/libtransmission/ipcparse.c b/libtransmission/ipcparse.c
index 5c1c3d555..3290a557f 100644
--- a/libtransmission/ipcparse.c
+++ b/libtransmission/ipcparse.c
@@ -1126,6 +1126,8 @@ gotmsg( struct ipc_info * info, benc_val_t * name, benc_val_t * val,
             info->funcs->def( msg->id, val, tag, arg );
         }
     }
+    else if( NULL != info->funcs->def )
+        info->funcs->def( IPC__MSG_UNKNOWN, NULL, tag, arg );
 
     return 0;
 }
diff --git a/libtransmission/ipcparse.h b/libtransmission/ipcparse.h
index a624ceae8..5c2bab3dc 100644
--- a/libtransmission/ipcparse.h
+++ b/libtransmission/ipcparse.h
@@ -75,7 +75,8 @@ enum ipc_msg
     IPC_MSG_SUP,
     IPC_MSG_UPLIMIT,
     IPC_MSG_VERSION,
-    IPC__MSG_COUNT
+    IPC__MSG_COUNT,
+    IPC__MSG_UNKNOWN
 };
 
 #define IPC_INF_COMMENT         ( 1 << 0 )