diff --git a/zerver/tests/test_rate_limiter.py b/zerver/tests/test_rate_limiter.py
index 57c83b95f3..ad12e4620f 100644
--- a/zerver/tests/test_rate_limiter.py
+++ b/zerver/tests/test_rate_limiter.py
@@ -36,6 +36,8 @@ class RateLimitedTestObject(RateLimitedObject):
 
 
 class RateLimiterBackendBase(ZulipTestCase, ABC):
+    backend: Type[RateLimiterBackend]
+
     def setUp(self) -> None:
         self.requests_record: Dict[str, List[float]] = {}