diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 94676a48fdc..94481deec7e 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -6138,6 +6138,18 @@
             "url": "/_mozilla/css/test_variable_serialization_specified.html"
           }
         ],
+        "css/white-space-pre-line-long-line.html": [
+          {
+            "path": "css/white-space-pre-line-long-line.html",
+            "url": "/_mozilla/css/white-space-pre-line-long-line.html"
+          }
+        ],
+        "css/white-space-pre-wrap-long-line.html": [
+          {
+            "path": "css/white-space-pre-wrap-long-line.html",
+            "url": "/_mozilla/css/white-space-pre-wrap-long-line.html"
+          }
+        ],
         "mozilla/DOMParser.html": [
           {
             "path": "mozilla/DOMParser.html",
diff --git a/tests/wpt/mozilla/tests/css/white-space-pre-line-long-line.html b/tests/wpt/mozilla/tests/css/white-space-pre-line-long-line.html
new file mode 100644
index 00000000000..bf0d0085fef
--- /dev/null
+++ b/tests/wpt/mozilla/tests/css/white-space-pre-line-long-line.html
@@ -0,0 +1,20 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>White space pre-line crashtest (#12369)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<style>
+div {
+   width: 70px;
+   white-space: pre-line;
+}
+</style>
+<div>This is an actual loooooooong line
+Line 2</div>
+<script>
+async_test(function(t) {
+  window.addEventListener('load', function() {
+    t.done();
+  });
+});
+</script>
diff --git a/tests/wpt/mozilla/tests/css/white-space-pre-wrap-long-line.html b/tests/wpt/mozilla/tests/css/white-space-pre-wrap-long-line.html
new file mode 100644
index 00000000000..f965a31a209
--- /dev/null
+++ b/tests/wpt/mozilla/tests/css/white-space-pre-wrap-long-line.html
@@ -0,0 +1,20 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>White space pre-wrap crashtest (#12369)</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<style>
+div {
+   width: 70px;
+   white-space: pre-wrap;
+}
+</style>
+<div>This is an actual loooooooong line
+Line 2</div>
+<script>
+async_test(function(t) {
+  window.addEventListener('load', function() {
+    t.done();
+  });
+});
+</script>
