diff --git a/src/libCom/osi/os/vxWorks/osdMutex.c b/src/libCom/osi/os/vxWorks/osdMutex.c
index 6b4920c48..6ef668627 100644
--- a/src/libCom/osi/os/vxWorks/osdMutex.c
+++ b/src/libCom/osi/os/vxWorks/osdMutex.c
@@ -16,13 +16,14 @@
 #include <time.h>
 #include <objLib.h>
 #include <sysLib.h>
+
 /* The following not defined in an vxWorks header */
 int sysClkRateGet(void);
 
 
 #include "epicsMutex.h"
 
-epicsMutexOSD * epicsMutexOsdCreate(void)
+struct epicsMutexOSD * epicsMutexOsdCreate(void)
 {
     return((epicsMutexId)
         semMCreate(SEM_DELETE_SAFE|SEM_INVERSION_SAFE|SEM_Q_PRIORITY));