diff --git a/src/libCom/errInc.c b/src/libCom/errInc.c
index d39b91f8e..bbd567128 100644
--- a/src/libCom/errInc.c
+++ b/src/libCom/errInc.c
@@ -18,6 +18,7 @@
 #include "dbStaticLib.h"
 #include "drvEpvxi.h"
 #include "devLib.h"
+#include "casdef.h"
 #include "errMdef.h"
 #ifdef VXLIST
 /* epics vxWorks  only*/