diff --git a/src/cas/generic/casdef.h b/src/cas/generic/casdef.h
index 91a483ba3..8481a1fa7 100644
--- a/src/cas/generic/casdef.h
+++ b/src/cas/generic/casdef.h
@@ -108,6 +108,7 @@ enum pvExistReturnEnum { pverExistsHere, pverDoesNotExistHere,
     pverAsyncCompletion };
 
 class casPV;
+class casPVI;
 class casCtx;
 class casChannel;