diff --git a/tests/test_rbac_comprehensive.py b/tests/test_rbac_comprehensive.py
index d79f48d..d66f42c 100644
--- a/tests/test_rbac_comprehensive.py
+++ b/tests/test_rbac_comprehensive.py
@@ -1200,6 +1200,11 @@ async def mail_app(engine: AsyncEngine, redis_client):
         await session.commit()
     yield app
     await close_engine()
+    # Suite isolation: close_engine() disposed AND nulled all global engines,
+    # which broke every downstream suite with 'relation users does not exist'.
+    # Restore the conftest engine as the global engine so downstream suites
+    # keep working (mirrors the production bootstrap).
+    reset_engine_for_testing(engine)
 
 
 @pytest_asyncio.fixture