diff --git a/src/libCom/osi/os/posix/osdThread.c b/src/libCom/osi/os/posix/osdThread.c
index 954e04dc9..501826715 100644
--- a/src/libCom/osi/os/posix/osdThread.c
+++ b/src/libCom/osi/os/posix/osdThread.c
@@ -514,7 +514,7 @@ static epicsThreadOSD *createImplicit(void)
     int status;
 
     tid = pthread_self();
-    sprintf(name, "non-EPICS_%d", (int)tid);
+    sprintf(name, "non-EPICS_%ld", (long)tid);
     pthreadInfo = create_threadInfo(name);
     pthreadInfo->tid = tid;
     pthreadInfo->osiPriority = 0;