diff --git a/web-share/share-sharePromise-internal-slot.html b/web-share/share-sharePromise-internal-slot.html
new file mode 100644
index 00000000000000..5a71eaa4abf359
--- /dev/null
+++ b/web-share/share-sharePromise-internal-slot.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="utf-8" />
+    <link rel="help" href="https://github.com/w3c/web-share/pull/113" />
+    <title>WebShare Test: only one share at a time</title>
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+    <script src="/resources/testdriver.js"></script>
+    <script src="/resources/testdriver-vendor.js"></script>
+  </head>
+  <body>
+    <script>
+      promise_test(async t => {
+        const [, promise2, promise3] = await test_driver.bless(
+          "share needs user activation",
+          () => {
+            return [
+              navigator.share({ title: "should be pending" }),
+              navigator.share({ title: "should reject" }),
+              navigator.share({ title: "should also reject" }),
+            ];
+          }
+        );
+        await Promise.all([
+          promise_rejects(t, "InvalidStateError", promise2),
+          promise_rejects(t, "InvalidStateError", promise3),
+        ]);
+      }, "Only allow one share call at a time, which is controlled by the [[sharePromise]] internal slot.");
+    </script>
+  </body>
+</html>
