diff --git a/src/libCom/osi/os/vxWorks/osdMutex.c b/src/libCom/osi/os/vxWorks/osdMutex.c
index 6ef668627..38db2ab83 100644
--- a/src/libCom/osi/os/vxWorks/osdMutex.c
+++ b/src/libCom/osi/os/vxWorks/osdMutex.c
@@ -25,7 +25,7 @@ int sysClkRateGet(void);
 
 struct epicsMutexOSD * epicsMutexOsdCreate(void)
 {
-    return((epicsMutexId)
+    return((struct epicsMutexOSD *)
         semMCreate(SEM_DELETE_SAFE|SEM_INVERSION_SAFE|SEM_Q_PRIORITY));
 }