diff --git a/src/i830_video.c b/src/i830_video.c
index beec03ea..8c2d804a 100644
--- a/src/i830_video.c
+++ b/src/i830_video.c
@@ -1016,6 +1016,7 @@ I830StopVideo(ScrnInfoPtr pScrn, pointer data, Bool shutdown)
 	 */
 	I830Sync(pScrn);
 	i830_free_memory(pScrn, pPriv->buf);
+	pPriv->buf = NULL;
 	pPriv->videoStatus = 0;
     } else {
 	if (pPriv->videoStatus & CLIENT_VIDEO_ON) {