diff --git a/src/i830_video.c b/src/i830_video.c
index 5325bbd..a8c8f3a 100644
--- a/src/i830_video.c
+++ b/src/i830_video.c
@@ -2574,6 +2574,7 @@ I830VideoBlockHandler(int i, pointer blockData, pointer pTimeout,
 		 */
 		I830Sync(pScrn);
 		i830_free_memory(pScrn, pPriv->buf);
+		pPriv->buf = NULL;
 		pPriv->videoStatus = 0;
 	    }
 	}