1 files changed, 1 insertions, 1 deletions
diff --git a/synapse/util/macaroons.py b/synapse/util/macaroons.py
index d1f76e3dc5..84e4f6ff55 100644
--- a/synapse/util/macaroons.py
+++ b/synapse/util/macaroons.py
@@ -77,7 +77,7 @@ def satisfy_expiry(v: pymacaroons.Verifier, get_time_ms: Callable[[], int]) -> N
             should be considered expired. Normally the current time.
     """
 
-    def verify_expiry_caveat(caveat: str):
+    def verify_expiry_caveat(caveat: str) -> bool:
         time_msec = get_time_ms()
         prefix = "time < "
         if not caveat.startswith(prefix):