diff --git a/src/libCom/osi/epicsMutex.c b/src/libCom/osi/epicsMutex.c
index b24d0fda1..2fbd3fc9a 100644
--- a/src/libCom/osi/epicsMutex.c
+++ b/src/libCom/osi/epicsMutex.c
@@ -117,7 +117,7 @@ void epicsShareAPI epicsMutexShowAll(int onlyLocked,unsigned  int level)
             }
         }
         printf("epicsMutexId %p source %s line %d\n",
-            pmutexNode->id,pmutexNode->pFileName,pmutexNode->lineno);
+            (void *)pmutexNode->id,pmutexNode->pFileName,pmutexNode->lineno);
         epicsMutexShow(pmutexNode->id,level);
         pmutexNode = (mutexNode *)ellNext(&pmutexNode->node);
     }
diff --git a/src/libCom/osi/os/posix/osdMutex.c b/src/libCom/osi/os/posix/osdMutex.c
index ca6e83f2a..2937d9fc5 100644
--- a/src/libCom/osi/os/posix/osdMutex.c
+++ b/src/libCom/osi/os/posix/osdMutex.c
@@ -201,5 +201,5 @@ epicsMutexLockStatus epicsMutexTryLock(epicsMutexId pmutex)
 void epicsMutexShow(epicsMutexId pmutex,unsigned int level)
 {
     printf("ownerTid %p count %d owned %d\n",
-        pmutex->ownerTid,pmutex->count,pmutex->owned);
+        (void *)pmutex->ownerTid,pmutex->count,pmutex->owned);
 }