diff --git a/testing/web-platform/tests/webauthn/idlharness-manual.https.window.js b/testing/web-platform/tests/webauthn/idlharness-manual.https.window.js
new file mode 100644
index 000000000000..884702753d84
--- /dev/null
+++ b/testing/web-platform/tests/webauthn/idlharness-manual.https.window.js
@@ -0,0 +1,53 @@
+// META: timeout=long
+// META: script=/resources/WebIDLParser.js
+// META: script=/resources/idlharness.js
+// META: script=helpers.js
+
+// https://w3c.github.io/webauthn/
+
+'use strict';
+
+idl_test(
+  ['webauthn'],
+  ['credential-management'],
+  async idlArray => {
+    idlArray.add_untested_idls("[Exposed=(Window,Worker)] interface ArrayBuffer {};");
+
+    idlArray.add_objects({
+      PublicKeyCredential: ['cred', 'assertion'],
+      AuthenticatorAttestationResponse: ['cred.response'],
+      AuthenticatorAssertionResponse: ['assertion.response']
+    });
+
+    const challengeBytes = new Uint8Array(16);
+    window.crypto.getRandomValues(challengeBytes);
+
+    self.cred = await Promise.race([
+      new Promise((_, reject) => window.setTimeout(() => {
+        reject('Timed out waiting for user to touch security key')
+      }, 3000)),
+      createCredential({
+        options: {
+          publicKey: {
+            timeout: 3000,
+            user: {
+              id: new Uint8Array(16),
+            },
+          }
+        }
+      }),
+    ]);
+
+    self.assertion = await navigator.credentials.get({
+      publicKey: {
+        timeout: 3000,
+        allowCredentials: [{
+          id: cred.rawId,
+          transports: ["usb", "nfc", "ble"],
+          type: "public-key"
+        }],
+        challenge: challengeBytes,
+      }
+    });
+  }
+);
diff --git a/testing/web-platform/tests/webauthn/idlharness.https.window.js b/testing/web-platform/tests/webauthn/idlharness.https.window.js
index fa5e812eeee1..ff0efcb656a7 100644
--- a/testing/web-platform/tests/webauthn/idlharness.https.window.js
+++ b/testing/web-platform/tests/webauthn/idlharness.https.window.js
@@ -11,38 +11,11 @@ idl_test(
   ['webauthn'],
   ['credential-management'],
   async idlArray => {
-    idlArray.add_untested_idls("[Exposed=(Window,Worker)] interface ArrayBuffer {};");
-    idlArray.add_objects({
-      WebAuthentication: ['navigator.authentication'],
-      PublicKeyCredential: ['cred', 'assertion'],
-      AuthenticatorAttestationResponse: ['cred.response'],
-      AuthenticatorAssertionResponse: ['assertion.response']
-    });
-
-    const challengeBytes = new Uint8Array(16);
-    window.crypto.getRandomValues(challengeBytes);
-
-    self.cred = await createCredential({
-      options: {
-        publicKey: {
-          timeout: 3000,
-          user: {
-            id: new Uint8Array(16),
-          },
-        }
-      }
-    });
-
-    self.assertion = await navigator.credentials.get({
-      publicKey: {
-        timeout: 3000,
-        allowCredentials: [{
-          id: cred.rawId,
-          transports: ["usb", "nfc", "ble"],
-          type: "public-key"
-        }],
-        challenge: challengeBytes,
-      }
-    });
+    // NOTE: The following are tested in idlharness-manual.https.window.js:
+    // idlArray.add_objects({
+    //   PublicKeyCredential: ['cred', 'assertion'],
+    //   AuthenticatorAttestationResponse: ['cred.response'],
+    //   AuthenticatorAssertionResponse: ['assertion.response']
+    // });
   }
 );