diff --git a/src/ca/cacIO.h b/src/ca/cacIO.h
index 8e7a4e76d..088ea1ff3 100644
--- a/src/ca/cacIO.h
+++ b/src/ca/cacIO.h
@@ -175,6 +175,7 @@ public:
     class notConnected {};
     class unsupportedByService {};
     class msgBodyCacheTooSmall {}; // hopefully this one goes away in the future
+    class requestTimedOut {};
 
 private:
     cacChannelNotify & callback;