1 files changed, 5 insertions, 1 deletions
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 23502eda70..b793fc4df7 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -22,7 +22,7 @@ import six
 from twisted.internet import defer, reactor
 from twisted.python.failure import Failure
 
-from synapse.api.constants import EventTypes, Membership
+from synapse.api.constants import EventTypes, Membership, MAX_DEPTH
 from synapse.api.errors import AuthError, Codes, SynapseError
 from synapse.crypto.event_signing import add_hashes_and_signatures
 from synapse.events.utils import serialize_event
@@ -625,6 +625,10 @@ class EventCreationHandler(object):
 
         if prev_events_and_hashes:
             depth = max([d for _, _, d in prev_events_and_hashes]) + 1
+            # we cap depth of generated events, to ensure that they are not
+            # rejected by other servers (and so that they can be persisted in
+            # the db)
+            depth = min(depth, MAX_DEPTH)
         else:
             depth = 1