diff --git a/game.c b/game.c
index b0f3c4f..3af4735 100644
--- a/game.c
+++ b/game.c
@@ -53,7 +53,7 @@ game game_copy(cgame g1) {
 	game g2 = game_new_empty_ext(g1->height, g1->width, g1->wrapping);
 	for (int i = 0; i < g2->height; i++) {
 		for (int j = 0; j < g2->width; j++) {
-			if (g1->tab_cell[i][j] == (S_BLANK | S_LIGHTBULB | S_MARK)){
+			if (g1->tab_cell[i][j] == S_BLANK || g1->tab_cell[i][j] == S_LIGHTBULB || g1->tab_cell[i][j] == S_MARK){
 				game_play_move(g2, i, j, g1->tab_cell[i][j]);
 			}
 			else {
@@ -172,6 +172,7 @@ void game_play_move(game g, uint i, uint j, square s) {
 	}
 	else {
 		g->hist = history_next(history_insert_after(g->hist,g->hist,s,i,j));
+		g->hist = history_delete_all_after(g->hist, g->hist);
 	}
 }
 
diff --git a/game_ext.c b/game_ext.c
index ee7854e..9dca5b1 100644
--- a/game_ext.c
+++ b/game_ext.c
@@ -56,6 +56,14 @@ bool game_is_wrapping(cgame g) {
 }
 
 void game_undo(game g) {
+	if (history_prev(g->hist) == NULL){
+		printf("waiting for your first move");
+	}
+	else{
+	game_set_square(g, history_i(history_prev(g->hist)), history_j(history_prev(g->hist)), history_state(history_prev(g->hist)));
+	game_update_flags(g);
+	g->hist = history_prev(g->hist);
+	}
 	return;
 }