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diff --git a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/module/inline-async-inserted-execorder.html b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/module/inline-async-inserted-execorder.html
new file mode 100644
index 0000000000..0f51fd318b
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/module/inline-async-inserted-execorder.html
@@ -0,0 +1,70 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>Inline async="" module scripts execute or throw parse errors asynchronously</title>
+<link rel="help" href="https://github.com/whatwg/html/issues/9864">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<body>
+<script>
+"use strict";
+setup({ allow_uncaught_exception: true });
+
+promise_test(async t => {
+  window.log = ["before any script execution"];
+
+  window.addEventListener("error", ev => {
+    window.log.push("error event on Window");
+  });
+
+  const noErrorScript = document.createElement("script");
+  noErrorScript.type = "module";
+  noErrorScript.async = true;
+  noErrorScript.textContent = "window.log.push('no error script executed');";
+
+  // This should queue a task to run the script, but not run it immediately.
+  document.head.append(noErrorScript);
+
+  log.push("after inserting noErrorScript");
+  assert_array_equals(window.log, [
+    "before any script execution",
+    "after inserting noErrorScript"
+  ]);
+
+  const parseErrorScript = document.createElement("script");
+  parseErrorScript.type = "module";
+  parseErrorScript.async = true;
+  parseErrorScript.textContent = "+++++";
+
+  // This should queue a task to fire the error event, but not fire it immediately.
+  document.head.append(parseErrorScript);
+
+  log.push("after inserting parseErrorScript");
+  assert_array_equals(window.log, [
+    "before any script execution",
+    "after inserting noErrorScript",
+    "after inserting parseErrorScript"
+  ]);
+
+  // After a microtask, the script run / error event must not happen.
+  queueMicrotask(t.step_func(() => {
+    assert_array_equals(window.log, [
+      "before any script execution",
+      "after inserting noErrorScript",
+      "after inserting parseErrorScript"
+    ]);
+  }));
+
+  // But it must eventually happen, after a full task.
+  await t.step_wait(() => window.log.length == 5, "5 items must eventually be logged");
+
+  // And when it does the order must be correct.
+  assert_array_equals(window.log, [
+    "before any script execution",
+    "after inserting noErrorScript",
+    "after inserting parseErrorScript",
+    "no error script executed",
+    "error event on Window"
+  ]);
+});
+</script>