diff --git a/src/gallium/state_trackers/xorg/xorg_driver.c b/src/gallium/state_trackers/xorg/xorg_driver.c
index 4c66354ad45..12915912986 100644
--- a/src/gallium/state_trackers/xorg/xorg_driver.c
+++ b/src/gallium/state_trackers/xorg/xorg_driver.c
@@ -466,6 +466,10 @@ static void drv_block_handler(int i, pointer blockData, pointer pTimeout,
           ms->screen->fence_reference(ms->screen,
                                       &ms->fence[j],
                                       ms->fence[j+1]);
+
+       ms->screen->fence_reference(ms->screen,
+                                   &ms->fence[XORG_NR_FENCES-1],
+                                   NULL);
     }