diff --git a/src/easystar.js b/src/easystar.js
index 8323066..d45bfdb 100755
--- a/src/easystar.js
+++ b/src/easystar.js
@@ -533,9 +533,9 @@ EasyStar.js = function() {
             var dx = Math.abs(x1 - x2);
             var dy = Math.abs(y1 - y2);
             if (dx < dy) {
-                return DIAGONAL_COST * dx + dy;
+                return DIAGONAL_COST * dx + (dy-dx);
             } else {
-                return DIAGONAL_COST * dy + dx;
+                return DIAGONAL_COST * dy + (dx-dy);
             }
         } else {
             // Manhattan distance