diff --git a/cpp/src/board.cpp b/cpp/src/board.cpp
index 6630eb5..96a3ddf 100644
--- a/cpp/src/board.cpp
+++ b/cpp/src/board.cpp
@@ -186,7 +186,7 @@ Board Board::make_move(Move move) const {
         ret.squares[move.target_square - 8] = Piece::None;
 
     // -- Handle promotion
-    if (move.promoting_to != 0)
+    if (move.promoting_to != Piece::None)
         ret.squares[move.target_square] = move.promoting_to;
 
     // -- Set en passant target if need