diff --git a/protocol.py b/protocol.py
index c0e94adf..6ad0b846 100644
--- a/protocol.py
+++ b/protocol.py
@@ -350,6 +350,7 @@ class Protocol:
         logger.info(f'No matching protocol found for {id} !')
         return None
 
+    @cached(LRUCache(20000), lock=Lock())
     @staticmethod
     def for_handle(handle):
         """Returns the protocol for a given handle.
diff --git a/tests/testutil.py b/tests/testutil.py
index e1fcd216..e76c5517 100644
--- a/tests/testutil.py
+++ b/tests/testutil.py
@@ -264,6 +264,7 @@ class TestCase(unittest.TestCase, testutil.Asserts):
         did.resolve_web.cache.clear()
         ids.web_ap_base_domain.cache.clear()
         protocol.Protocol.for_id.cache.clear()
+        protocol.Protocol.for_handle.cache.clear()
         User.count_followers.cache.clear()
 
         for cls in ExplicitEnableFake, Fake, OtherFake: