1 files changed, 3 insertions, 0 deletions
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index 1e1ce87e0e..5d6f7dfa28 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -227,6 +227,9 @@ class StateStore(SQLBaseStore):
                     ],
                 )
 
+            # Prefill the state group cache with this group.
+            # It's fine to use the sequence like this as the state group map
+            # is immutable.
             txn.call_after(
                 self._state_group_cache.update,
                 self._state_group_cache.sequence,