diff --git a/berserk/clients/opening_explorer.py b/berserk/clients/opening_explorer.py
index 29cae77..2f63089 100644
--- a/berserk/clients/opening_explorer.py
+++ b/berserk/clients/opening_explorer.py
@@ -197,11 +197,11 @@ def stream_player_games(
         for response in self._r.get(path, params=params, stream=True):
             yield cast(OpeningStatistic, response)
 
-    def get_otb_master_game(self, game_id: str):
+    def get_otb_master_game(self, game_id: str) -> str:
         """Get PGN representation of an over-the-board master game.
 
         :param game_id: game ID
         :return: PGN of the game
         """
         path = f"/master/pgn/{game_id}"
-        return self._r.get(path)
+        return str(self._r.get(path))