diff --git a/tests/wpt/meta/MANIFEST.json b/tests/wpt/meta/MANIFEST.json
index 0e367d5653e..3a7faebb345 100644
--- a/tests/wpt/meta/MANIFEST.json
+++ b/tests/wpt/meta/MANIFEST.json
@@ -727275,6 +727275,13 @@
          {}
         ]
        ],
+       "slot-element-default-display.html": [
+        "825efaa1a97d898c9cb2b7db1c18b3213c8ed214",
+        [
+         null,
+         {}
+        ]
+       ],
        "slot-element-focusable.tentative.html": [
         "b6d2449e890b31a9fc50712422c0dbca5e3e33a0",
         [
diff --git a/tests/wpt/tests/html/rendering/non-replaced-elements/flow-content-0/slot-element-default-display.html b/tests/wpt/tests/html/rendering/non-replaced-elements/flow-content-0/slot-element-default-display.html
new file mode 100644
index 00000000000..825efaa1a97
--- /dev/null
+++ b/tests/wpt/tests/html/rendering/non-replaced-elements/flow-content-0/slot-element-default-display.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<title>CSS Test (Display): <slot> elements default display should be contents</title>
+<link rel="help" href="https://html.spec.whatwg.org/multipage/rendering.html#flow-content-3">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+
+<script>
+    test(() => {
+        let host = document.body.appendChild(document.createElement("div"));
+        let slot = host.attachShadow({ mode: "open" }).appendChild(document.createElement("slot"));
+        let cs = getComputedStyle(slot);
+        assert_equals(cs.getPropertyValue("display"), "contents", "slot default display is not contents");
+        document.body.removeChild(host);
+    }, `slot element with default display should be contents`);
+
+</script>
