diff --git a/hw/vmware_vga.c b/hw/vmware_vga.c
index 54c320a..f2ffa21 100644
--- a/hw/vmware_vga.c
+++ b/hw/vmware_vga.c
@@ -291,12 +291,33 @@
                 int x, int y, int w, int h)
 {
 #ifndef DIRECT_VRAM
-    int line = h;
-    int bypl = s->bypp * s->width;
-    int width = s->bypp * w;
-    int start = s->bypp * x + bypl * y;
-    uint8_t *src = s->vram + start;
-    uint8_t *dst = s->ds->data + start;
+    int line;
+    int bypl;
+    int width;
+    int start;
+    uint8_t *src;
+    uint8_t *dst;
+
+    if (x + w > s->width) {
+        fprintf(stderr, "%s: update width too large x: %d, w: %d\n",
+                        __FUNCTION__, x, w);
+        x = MIN(x, s->width);
+        w = s->width - x;
+    }
+
+    if (y + h > s->height) {
+        fprintf(stderr, "%s: update height too large y: %d, h: %d\n",
+                        __FUNCTION__, y, h);
+        y = MIN(y, s->height);
+        h = s->height - y;
+    }
+
+    line = h;
+    bypl = s->bypp * s->width;
+    width = s->bypp * w;
+    start = s->bypp * x + bypl * y;
+    src = s->vram + start;
+    dst = s->ds->data + start;
 
     for (; line > 0; line --, src += bypl, dst += bypl)
         memcpy(dst, src, width);