diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c b/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c
index 5fa13267bd9f427b7f83251f22e6bd13a80683b3..02e369f80449a2d222375349aa4937623f2ac9e7 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/nv50.c
@@ -544,13 +544,13 @@ nv50_disp_curs_ofuncs = {
 static void
 nv50_disp_base_vblank_enable(struct nouveau_event *event, int head)
 {
-	nv_mask(event->priv, 0x61002c, (1 << head), (1 << head));
+	nv_mask(event->priv, 0x61002c, (4 << head), (4 << head));
 }
 
 static void
 nv50_disp_base_vblank_disable(struct nouveau_event *event, int head)
 {
-	nv_mask(event->priv, 0x61002c, (1 << head), (0 << head));
+	nv_mask(event->priv, 0x61002c, (4 << head), 0);
 }
 
 static int