diff --git a/src/ca/cac.cpp b/src/ca/cac.cpp
index fb78cf169..9f2b8d81f 100644
--- a/src/ca/cac.cpp
+++ b/src/ca/cac.cpp
@@ -44,7 +44,7 @@
 #include "bhe.h"
 #include "net_convert.h"
 #include "autoPtrFreeList.h"
-#include "noopIIU.h"
+#include "noopiiu.h"
 
 static const char *pVersionCAC = 
     "@(#) " EPICS_VERSION_STRING