Reduce the number of "untyped defs" (#12716)

1 files changed, 1 insertions, 1 deletions

diff --git a/synapse/storage/prepare_database.py b/synapse/storage/prepare_database.py

index 546d6bae6e..c33df42084 100644
--- a/synapse/storage/prepare_database.py
+++ b/synapse/storage/prepare_database.py
@@ -85,7 +85,7 @@ def prepare_database(
     database_engine: BaseDatabaseEngine,
     config: Optional[HomeServerConfig],
     databases: Collection[str] = ("main", "state"),
-):
+) -> None:
     """Prepares a physical database for usage. Will either create all necessary tables
     or upgrade from an older schema version.