1 files changed, 6 insertions, 1 deletions
diff --git a/synapse/types.py b/synapse/types.py
index 65e4d8c181..f3cd465735 100644
--- a/synapse/types.py
+++ b/synapse/types.py
@@ -17,7 +17,7 @@ import re
 import string
 import sys
 from collections import namedtuple
-from typing import Dict, Tuple, TypeVar
+from typing import Any, Dict, Tuple, TypeVar
 
 import attr
 from signedjson.key import decode_verify_key_bytes
@@ -43,6 +43,11 @@ T = TypeVar("T")
 StateMap = Dict[Tuple[str, str], T]
 
 
+# the type of a JSON-serialisable dict. This could be made stronger, but it will
+# do for now.
+JsonDict = Dict[str, Any]
+
+
 class Requester(
     namedtuple(
         "Requester", ["user", "access_token_id", "is_guest", "device_id", "app_service"]