diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c
index d54fb06..2725264 100644
--- a/hw/display/cirrus_vga.c
+++ b/hw/display/cirrus_vga.c
@@ -293,6 +293,10 @@
     assert(s->cirrus_blt_width > 0);
     assert(s->cirrus_blt_height > 0);
 
+    if (s->cirrus_blt_width > CIRRUS_BLTBUFSIZE) {
+        return true;
+    }
+
     if (blit_region_is_unsafe(s, s->cirrus_blt_dstpitch,
                               s->cirrus_blt_dstaddr & s->cirrus_addr_mask)) {
         return true;