diff --git a/dither4.s b/dither4.s
index 067544c..58f4d41 100644
--- a/dither4.s
+++ b/dither4.s
@@ -69,8 +69,9 @@ wait_vblank:
     sta SDMCTL
 
 wait_start:
+    sta WSYNC
     lda VCOUNT
-    cmp #12
+    cmp #15
     bne wait_start
     ldy #0