diff --git a/src/ca/CASG.cpp b/src/ca/CASG.cpp
index 11dcf9289..75a42c74d 100644
--- a/src/ca/CASG.cpp
+++ b/src/ca/CASG.cpp
@@ -133,7 +133,7 @@ void CASG::reset ()
 
 void CASG::show ( unsigned level ) const
 {
-    printf ( "Sync Group: id=%u, magic=%u, opPend=%lu\n",
+    printf ( "Sync Group: id=%u, magic=%u, opPend=%u\n",
         this->getId (), this->magic, this->ioList.count () );
     if ( level ) {
         epicsAutoMutex locker ( this->mutex );