diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 9f3589df210..0011946fd48 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -32655,6 +32655,12 @@
      {}
     ]
    ],
+   "css/issue_18544_flow_list_crash.html": [
+    [
+     "/_mozilla/css/issue_18544_flow_list_crash.html",
+     {}
+    ]
+   ],
    "css/matchMedia.html": [
     [
      "/_mozilla/css/matchMedia.html",
@@ -63320,6 +63326,10 @@
    "863e3c8c5ffa1627a20f51e89b7eca884ea381dd",
    "reftest"
   ],
+  "css/issue_18544_flow_list_crash.html": [
+   "9e41b681e414db9bd5f3fc75210de12a6e660c28",
+   "testharness"
+  ],
   "css/jpeg_normal.html": [
    "4e9d02f232492b55f8e6b71046b392c4dc2c9fb6",
    "reftest"
diff --git a/tests/wpt/mozilla/tests/css/issue_18544_flow_list_crash.html b/tests/wpt/mozilla/tests/css/issue_18544_flow_list_crash.html
new file mode 100644
index 00000000000..9ef57cad02a
--- /dev/null
+++ b/tests/wpt/mozilla/tests/css/issue_18544_flow_list_crash.html
@@ -0,0 +1,16 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>Issue 18544 - Flow list crash</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div style="position:fixed"></div>
+<script>
+  async_test(function(test) {
+    window.onload = test.step_func_done(function() {
+      document.body.children[0].style['column-count'] = 1;
+      document.body.offsetTop;
+      assert_true(true, "Did not crash");
+    });
+  });
+</script>
+
