diff --git a/index.js b/index.js
index ac22e13..8b6e8f8 100644
--- a/index.js
+++ b/index.js
@@ -14,7 +14,10 @@ import createBoard from './src/board/create-board.js';
 import * as validation from './src/validation.js';
 import findAllMoves from './src/validation/all-moves.js';
 import isCheck from './src/validation/is-check.js';
-import gameEndingStatus from './src/validation/ending';
+
+import gameEndingStatus from './src/validation/ending.js';
+import undo from './src/board/undo.js'
+
 export default {
 	setupBoard,
 	createBoard,
diff --git a/package.json b/package.json
index 19814f8..07cec8d 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "fenfurnace",
-	"version": "0.1.1",
+	"version": "0.1.2",
 	"description": "A chess engine designed to work entirely from a FEN position.",
 	"main": "index.js",
 	"type": "module",
diff --git a/src/validation.js b/src/validation.js
index 2ffd043..f5c2d5d 100644
--- a/src/validation.js
+++ b/src/validation.js
@@ -172,7 +172,7 @@ export function makeMove(startCell, endCell, { isTest } = {}) {
 	} else {
 		global.enpassantSquare = '-';
 	}
-
+	//check checker
 	if (isCheck(global.currentTurn)) {
 		global.boardArray = beforeState;
 		return false;
diff --git a/src/validation/is-check.js b/src/validation/is-check.js
index 90fd4b6..3476a2a 100644
--- a/src/validation/is-check.js
+++ b/src/validation/is-check.js
@@ -24,9 +24,9 @@ export default function isCheck(colour) {
 
 			const pieceColour = pieces.getColour(cell);
 			if (
-				((pieces.isWhite(pieceColour) && colour === 'b')
+				((pieceColour === 'w' && colour === 'b')
 				||
-				(pieces.isBlack(pieceColour) && colour === 'w'))
+				(pieceColour === 'b' && colour === 'w'))
 				&&
 				validation.validateMove(cell, kingCells[colour])
 			) {