diff --git a/src/ca/cacIO.h b/src/ca/cacIO.h
index e9795aa9c..376c7e9ce 100644
--- a/src/ca/cacIO.h
+++ b/src/ca/cacIO.h
@@ -114,7 +114,7 @@ private:
     bool f_operatorConfirmationRequest:1;
 };
 
-class epicsShareClass cacChannelNotify {
+class epicsShareClass cacChannelNotify { // X aCC 655
 public:
     virtual ~cacChannelNotify () = 0;
     virtual void connectNotify () = 0;