diff --git a/synapse/storage/databases/main/state.py b/synapse/storage/databases/main/state.py
index 9c443a8009b..06c44bb5631 100644
--- a/synapse/storage/databases/main/state.py
+++ b/synapse/storage/databases/main/state.py
@@ -765,7 +765,7 @@ def get(
             raise Exception("State map was filtered and doesn't include: %s", key)
         return super().get(key, default)
 
-    def __contains__(self, key: object) -> bool:
+    def __contains__(self, key: Any) -> bool:
         if key not in self.state_filter:
             raise Exception("State map was filtered and doesn't include: %s", key)
 
diff --git a/synapse/types/state.py b/synapse/types/state.py
index 36024e1b426..937ffe3f979 100644
--- a/synapse/types/state.py
+++ b/synapse/types/state.py
@@ -20,6 +20,7 @@
 import logging
 from typing import (
     TYPE_CHECKING,
+    Any,
     Callable,
     Collection,
     Dict,
@@ -584,12 +585,17 @@ def must_await_full_state(self, is_mine_id: Callable[[str], bool]) -> bool:
         # local users only
         return False
 
-    def __contains__(self, key: Tuple[str, str]) -> bool:
+    def __contains__(self, key: Any) -> bool:
+        if not isinstance(key, tuple) or len(key) != 2:
+            return False
+
         typ, state_key = key
+
         if typ in self.types:
             state_keys = self.types[typ]
             if state_keys is None or state_key in state_keys:
                 return True
+
         elif self.include_others:
             return True