diff --git a/hw/xfree86/drivers/video/modesetting/present.c b/hw/xfree86/drivers/video/modesetting/present.c
index 4777d3158a..47a4b7977e 100644
--- a/hw/xfree86/drivers/video/modesetting/present.c
+++ b/hw/xfree86/drivers/video/modesetting/present.c
@@ -323,6 +323,9 @@ ms_present_check_flip(RRCrtcPtr crtc,
     modesettingPtr ms = modesettingPTR(scrn);
     Bool async_flip = !sync_flip;
 
+    if (reason)
+        *reason = PRESENT_FLIP_REASON_UNKNOWN;
+
     if (ms->drmmode.sprites_visible > 0)
         goto no_flip;