diff --git a/CHANGELOG.md b/CHANGELOG.md
index 82416455..9ceab4d5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -131,6 +131,8 @@
 * Pressing a modifier key while the kitty keyboard protocol is enabled
   no longer resets the viewport, or clears the selection.
 * Crash when failing to load an xcursor image ([#1624][1624]).
+* Crash when resizing a dynamically sized sixel (no raster
+  attributes), with a non-1:1 aspect ratio.
 
 [1531]: https://codeberg.org/dnkl/foot/issues/1531
 [1573]: https://codeberg.org/dnkl/foot/issues/1573
diff --git a/sixel.c b/sixel.c
index c046145f..8ec72c15 100644
--- a/sixel.c
+++ b/sixel.c
@@ -1347,8 +1347,9 @@ resize_vertically(struct terminal *term, int new_height)
     uint32_t *old_data = term->sixel.image.data;
     const int width = term->sixel.image.width;
     const int old_height = term->sixel.image.height;
+    const int sixel_row_height = 6 * term->sixel.pan;
 
-    int alloc_height = (new_height + 6 - 1) / 6 * 6;
+    int alloc_height = (new_height + sixel_row_height - 1) / sixel_row_height * sixel_row_height;
 
     xassert(new_height > 0);