1 files changed, 1 insertions, 1 deletions
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 3278a695ed..6290f7f523 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -377,7 +377,7 @@ class MessageHandler:
         """
 
         expiry_ts = event.content.get(EventContentFields.SELF_DESTRUCT_AFTER)
-        if not isinstance(expiry_ts, int) or event.is_state():
+        if type(expiry_ts) is not int or event.is_state():
             return
 
         # _schedule_expiry_for_event won't actually schedule anything if there's already