diff --git a/src/FEN.php b/src/FEN.php
index 2f30192..dd2ac40 100644
--- a/src/FEN.php
+++ b/src/FEN.php
@@ -715,7 +715,7 @@ private function standard_move(Move &$move) : void
 
       $new_board->set_square($origin, '');
       if ($move->get_promotion()) {
-        $new_board->set_square($target, $move->get_promotion());
+        $new_board->set_square($target, Board::get_piece_of_color($move->get_promotion(), $this->get_active_color()));
       } else {
         $new_board->set_square($target, $piece);
         if ($move->get_piece_type() == 'P' && $target->export() == $this->get_en_passant()) {
@@ -733,8 +733,9 @@ private function standard_move(Move &$move) : void
 
     private function set_new_board(Board $new_board) : void
     {
-      if ($new_board->is_check($this->get_active_color())) {
-        throw new RulesException('King is in check.');
+      $active_color = $this->get_active_color();
+      if ($new_board->is_check($active_color)) {
+        throw new RulesException('King is in check. ' . $new_board->export() . ' ' . $active_color);
       }
       $this->set_board($new_board);
     }
diff --git a/tests/unit/FENTest.php b/tests/unit/FENTest.php
index 4850b01..8591152 100644
--- a/tests/unit/FENTest.php
+++ b/tests/unit/FENTest.php
@@ -304,6 +304,10 @@ public function testPromotion() : void
     $fen->set_board('1q5k/P7/8/8/8/8/8/K7');
     $fen->move('a8=Q');
     $this->assertEquals('Qq5k/8/8/8/8/8/8/K7', $fen->get_board());
+
+    $fen = new FEN('2Q5/8/8/8/p3Q3/P7/7p/1K4k1 b - - 0 53');
+    $fen->move('h1=Q');
+    $this->assertEquals('2Q5/8/8/8/p3Q3/P7/8/1K4kq', $fen->get_board());
   }
 
   public function testPromotionNotSpecified() : void