diff --git a/src/endgame.h b/src/endgame.h
index 8a42eda2..d7a7681a 100644
--- a/src/endgame.h
+++ b/src/endgame.h
@@ -89,7 +89,7 @@ struct Endgame : public EndgameBase<T> {
   T operator()(const Position&) const;
 
 private:
-  const Color strongSide, weakSide;
+  Color strongSide, weakSide;
 };