1 files changed, 4 insertions, 4 deletions
diff --git a/synapse/api/filtering.py b/synapse/api/filtering.py
index 102889ac49..f7f46f8d80 100644
--- a/synapse/api/filtering.py
+++ b/synapse/api/filtering.py
@@ -140,13 +140,13 @@ USER_FILTER_SCHEMA = {
 
 
 @FormatChecker.cls_checks("matrix_room_id")
-def matrix_room_id_validator(room_id_str: str) -> bool:
-    return RoomID.is_valid(room_id_str)
+def matrix_room_id_validator(room_id: object) -> bool:
+    return isinstance(room_id, str) and RoomID.is_valid(room_id)
 
 
 @FormatChecker.cls_checks("matrix_user_id")
-def matrix_user_id_validator(user_id_str: str) -> bool:
-    return UserID.is_valid(user_id_str)
+def matrix_user_id_validator(user_id: object) -> bool:
+    return isinstance(user_id, str) and UserID.is_valid(user_id)
 
 
 class Filtering: