diff --git a/.claude-plugin/marketplace.json b/.claude-plugin/marketplace.json
index c50900aa..bbc808de 100644
--- a/.claude-plugin/marketplace.json
+++ b/.claude-plugin/marketplace.json
@@ -1,5 +1,4 @@
 {
-  "$schema": "https://anthropic.com/claude-code/marketplace.schema.json",
   "name": "ponytail",
   "description": "Lazy senior dev mode for AI agents. The best code is the code you never wrote.",
   "owner": {
diff --git a/tests/package.test.js b/tests/package.test.js
index 1412bf26..1235c682 100644
--- a/tests/package.test.js
+++ b/tests/package.test.js
@@ -21,3 +21,12 @@ test('npm package ships the advertised cleanup script', () => {
     'scripts/uninstall.js is listed in files but missing on disk',
   );
 });
+
+test('Claude marketplace manifest does not depend on an external schema URL', () => {
+  const marketplace = JSON.parse(fs.readFileSync(path.join(root, '.claude-plugin', 'marketplace.json'), 'utf8'));
+  assert.equal(
+    Object.hasOwn(marketplace, '$schema'),
+    false,
+    'Claude Desktop marketplace sync fails when $schema points at an unreachable external URL',
+  );
+});