1 files changed, 4 insertions, 4 deletions
diff --git a/src/moves.cpp b/src/moves.cpp
index bba85e7..664971d 100644
--- a/src/moves.cpp
+++ b/src/moves.cpp
@@ -174,17 +174,17 @@ std::vector<Move> GetLegalMoves(Game *b) {
   std::vector<Move> legalMove;
   for (Move move : moves) {
     bool isLegal = true;
-    Game testBoard = *b;
-    PlayMove(move, &testBoard);
-    auto opponentResponse = GetPseudoLegalMoves(&testBoard);
+    UndoMove undo = MakeMove(move, b);
+    auto opponentResponse = GetPseudoLegalMoves(b);
     for (Move move : opponentResponse) {
-      if (testBoard.pieces[PositionToIndex(move.To)].type == KING) {
+      if (b->pieces[PositionToIndex(move.To)].type == KING) {
         isLegal = false;
       }
     }
     if (isLegal) {
       legalMove.push_back(move);
     };
+    UnMake(undo, b);
   }
   if (legalMove.size() == 0) {
     bool isCheck = false;