diff --git a/21g30t1e75.js b/21g30t1e75.js
index cd1aa3c..76bdd9b 100644
--- a/21g30t1e75.js
+++ b/21g30t1e75.js
@@ -906,7 +906,9 @@ GameLib.CustomCode.prototype.initializeGrid = function() {
         function(x) {
             x.map(
                 function(y) {
-                    y.dispose();
+					if (y) {
+                    	y.dispose();
+					}
                 }
             );
         }