diff --git a/src/libCom/osi/os/WIN32/osdEvent.c b/src/libCom/osi/os/WIN32/osdEvent.c
index 5feae1c0b..db703c565 100644
--- a/src/libCom/osi/os/WIN32/osdEvent.c
+++ b/src/libCom/osi/os/WIN32/osdEvent.c
@@ -142,7 +142,7 @@ epicsShareFunc epicsEventWaitStatus epicsShareAPI epicsEventWaitWithTimeout (
         tmo = 0u;
     }
     else {
-        tmo = ( DWORD ) ( timeOut * mSecPerSecOsdSem );
+        tmo = ( DWORD ) ( ( timeOut * mSecPerSecOsdSem ) + 0.5 );
     }
     status = WaitForSingleObject ( pSem->handle, tmo );
     if ( status == WAIT_OBJECT_0 ) {
diff --git a/src/libCom/osi/os/WIN32/osdThread.c b/src/libCom/osi/os/WIN32/osdThread.c
index c8dae5cb3..841e7789c 100644
--- a/src/libCom/osi/os/WIN32/osdThread.c
+++ b/src/libCom/osi/os/WIN32/osdThread.c
@@ -481,7 +481,7 @@ epicsShareFunc int epicsShareAPI epicsThreadIsSuspended (epicsThreadId id)
 epicsShareFunc void epicsShareAPI epicsThreadSleep (double seconds)
 {
     static const double mSecPerSec = 1000;
-    DWORD milliSecDelay = (DWORD) (seconds * mSecPerSec);
+    DWORD milliSecDelay = (DWORD) ( (seconds * mSecPerSec) + 0.5 );
     Sleep (milliSecDelay);
 }