diff --git a/hw/vga.c b/hw/vga.c
index 4d74ffe2d9..53b5ff6d0d 100644
--- a/hw/vga.c
+++ b/hw/vga.c
@@ -1837,7 +1837,8 @@ static void vga_update_display(void *opaque)
     if (ds_get_bits_per_pixel(s->ds) == 0) {
         /* nothing to do */
     } else {
-        full_update = 0;
+        full_update = s->full_update;
+        s->full_update = 0;
         if (!(s->ar_index & 0x20)) {
             graphic_mode = GMODE_BLANK;
         } else {
@@ -1867,8 +1868,7 @@ static void vga_invalidate_display(void *opaque)
 {
     VGAState *s = (VGAState *)opaque;
 
-    s->last_width = -1;
-    s->last_height = -1;
+    s->full_update = 1;
 }
 
 void vga_reset(void *opaque)
diff --git a/hw/vga_int.h b/hw/vga_int.h
index 631b1b0fc3..8fdf51dc61 100644
--- a/hw/vga_int.h
+++ b/hw/vga_int.h
@@ -158,6 +158,7 @@ typedef struct VGACommonState {
     uint32_t last_width, last_height; /* in chars or pixels */
     uint32_t last_scr_width, last_scr_height; /* in pixels */
     uint32_t last_depth; /* in bits */
+    uint8_t full_update;
     uint8_t cursor_start, cursor_end;
     uint32_t cursor_offset;
     unsigned int (*rgb_to_pixel)(unsigned int r,