diff --git a/pyalapin/engine/move.py b/pyalapin/engine/move.py
index f9499cb..ae57236 100644
--- a/pyalapin/engine/move.py
+++ b/pyalapin/engine/move.py
@@ -130,6 +130,11 @@ def to_pgn(self):
                 piece = "O-O-O"
                 start = ""
                 end = ""
+            else:
+                piece = "O-O"
+                start = ""
+                end = ""
+
         king = (
             self.board.white_king
             if not self.player.white_side