diff --git a/tests/test_plugin_contract.py b/tests/test_plugin_contract.py
index ba1f4a9..dd3b3f3 100644
--- a/tests/test_plugin_contract.py
+++ b/tests/test_plugin_contract.py
@@ -36,6 +36,7 @@ class TestPluginContract(unittest.TestCase):
 
         self.assertEqual(version, _skill_version())
         self.assertEqual(version, _json(ROOT / ".claude-plugin" / "plugin.json")["version"])
+        self.assertEqual(version, _json(ROOT / "gemini-extension.json")["version"])
 
         marketplace = _json(ROOT / ".claude-plugin" / "marketplace.json")
         plugins = marketplace.get("plugins") or []