new file mode 100644
--- /dev/null
+++ b/layout/style/crashtests/1401256.html
@@ -0,0 +1,5 @@
+<script>
+  let o1 = document.createElement('p');
+  document.documentElement.appendChild(o1);
+  o1.animate({'minWidth':['-moz-max-content']});
+</script>
\ No newline at end of file

--- a/layout/style/crashtests/crashtests.list
+++ b/layout/style/crashtests/crashtests.list
@@ -217,8 +217,9 @@ load 1397439-1.html
 load 1395719.html
 load 1397091.html
 load 1398479.html
 load 1398581.html
 load 1400035.html
 load 1399546.html
 load 1400325.html
 load 1400926.html
+load 1401256.html