diff --git a/src/ttt/infrastructure/adapters/games.py b/src/ttt/infrastructure/adapters/games.py
index d31e4ad..67a9fcd 100644
--- a/src/ttt/infrastructure/adapters/games.py
+++ b/src/ttt/infrastructure/adapters/games.py
@@ -20,7 +20,9 @@ async def game_with_game_location(
         join_condition = (TableUser.id == game_location_user_id) & (
             TableUser.game_location_game_id == TableGame.id
         )
-        stmt = select(TableGame).join(TableUser, join_condition)
+        stmt = (
+            select(TableGame).join(TableUser, join_condition).with_for_update()
+        )
 
         table_game = await self._session.scalar(stmt)
 
diff --git a/src/ttt/infrastructure/adapters/users.py b/src/ttt/infrastructure/adapters/users.py
index 5079439..08e0835 100644
--- a/src/ttt/infrastructure/adapters/users.py
+++ b/src/ttt/infrastructure/adapters/users.py
@@ -19,7 +19,7 @@ async def contains_user_with_id(
         id_: int,
         /,
     ) -> bool:
-        stmt = select(exists(1).where(TableUser.id == id_))
+        stmt = select(exists(1).where(TableUser.id == id_)).with_for_update()
 
         return bool(await self._session.execute(stmt))
 
@@ -50,6 +50,7 @@ async def users_with_ids(
         return tuple(users)
 
     async def user_with_id(self, id_: int, /) -> User | None:
-        table_user = await self._session.get(TableUser, id_)
+        stmt = select(TableUser).where(TableUser.id == id_).with_for_update()
+        table_user = await self._session.scalar(stmt)
 
         return None if table_user is None else table_user.entity()