2 files changed, 6 insertions, 2 deletions
diff --git a/synapse/__init__.py b/synapse/__init__.py
index 5ecce24eee..46902adab5 100644
--- a/synapse/__init__.py
+++ b/synapse/__init__.py
@@ -47,7 +47,7 @@ try:
 except ImportError:
     pass
 
-__version__ = "1.38.0"
+__version__ = "1.39.0rc1"
 
 if bool(os.environ.get("SYNAPSE_TEST_PATCH_LOG_CONTEXTS", False)):
     # We import here so that we don't have to install a bunch of deps when
diff --git a/synapse/storage/databases/main/lock.py b/synapse/storage/databases/main/lock.py
index 774861074c..3d1dff660b 100644
--- a/synapse/storage/databases/main/lock.py
+++ b/synapse/storage/databases/main/lock.py
@@ -78,7 +78,11 @@ class LockStore(SQLBaseStore):
         """Called when the server is shutting down"""
         logger.info("Dropping held locks due to shutdown")
 
-        for (lock_name, lock_key), token in self._live_tokens.items():
+        # We need to take a copy of the tokens dict as dropping the locks will
+        # cause the dictionary to change.
+        tokens = dict(self._live_tokens)
+
+        for (lock_name, lock_key), token in tokens.items():
             await self._drop_lock(lock_name, lock_key, token)
 
         logger.info("Dropped locks due to shutdown")