diff --git a/html/semantics/popups/popup-attribute-unscopable.tentative.html b/html/semantics/popups/popup-attribute-unscopable.tentative.html
deleted file mode 100644
index 91e46d86bd05d2..00000000000000
--- a/html/semantics/popups/popup-attribute-unscopable.tentative.html
+++ /dev/null
@@ -1,23 +0,0 @@
-<!DOCTYPE html>
-<meta charset="utf-8" />
-<title>Popup attribute is unscopable</title>
-<link rel="author" href="mailto:masonf@chromium.org">
-<link rel=help href="https://open-ui.org/components/popup.research.explainer">
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-
-<button onclick="popup()">Click me</button>
-<script>
-let clicked = false;
-function popup() {
-  clicked=true;
-}
-test(() => {
-  // If the `popup` attribute isn't unscopable, then the onclick handler
-  // will call `this.popup()` which will refer to the `popup` content attribute
-  // on HTMLButtonElement, rather than the `popup()` function.
-  assert_false(clicked);
-  document.querySelector('button').click();
-  assert_true(clicked);
-},'The `popup` attribute should be unscopable');
-</script>
