diff --git a/hw/display/artist.c b/hw/display/artist.c
index de56200dbf..a206afe641 100644
--- a/hw/display/artist.c
+++ b/hw/display/artist.c
@@ -555,7 +555,7 @@ static void fill_window(ARTISTState *s, int startx, int starty,
 static void draw_line(ARTISTState *s, int x1, int y1, int x2, int y2,
                       bool update_start, int skip_pix, int max_pix)
 {
-    struct vram_buffer *buf;
+    struct vram_buffer *buf = &s->vram_buffer[ARTIST_BUFFER_AP];
     uint8_t color;
     int dx, dy, t, e, x, y, incy, diago, horiz;
     bool c1;
@@ -563,6 +563,12 @@ static void draw_line(ARTISTState *s, int x1, int y1, int x2, int y2,
 
     trace_artist_draw_line(x1, y1, x2, y2);
 
+    if (x1 * y1 >= buf->size || x2 * y2 >= buf->size) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "draw_line (%d,%d) (%d,%d)\n", x1, y1, x2, y2);
+        return;
+    }
+
     if (update_start) {
         s->vram_start = (x2 << 16) | y2;
     }
@@ -620,7 +626,6 @@ static void draw_line(ARTISTState *s, int x1, int y1, int x2, int y2,
     x = x1;
     y = y1;
     color = artist_get_color(s);
-    buf = &s->vram_buffer[ARTIST_BUFFER_AP];
 
     do {
         if (c1) {