diff --git a/21g30t1e75.js b/21g30t1e75.js
index 99cc781..6c4a84d 100644
--- a/21g30t1e75.js
+++ b/21g30t1e75.js
@@ -330,13 +330,28 @@ GameLib.CustomCode.GameObject.prototype.applyToMesh = function(updateInstance) {
  */
 GameLib.CustomCode.prototype.getFreeGridPosition = function() {
 
-    var x = GameLib.Utils.GetRandomInt(0, GameLib.CustomCode.GRID_WIDTH);
-    var y = GameLib.Utils.GetRandomInt(0, GameLib.CustomCode.GRID_HEIGHT);
+	var positions = [];
+	
+	this.grid.map(
+		function(row, x) {
+			row.map(
+				function(object, y) {
+					if (object.objectType === GameLib.CustomCode.OBJECT_TYPE_NONE) {
+						positions.push(
+							{
+								x : x,
+								y : y
+							}
+						)
+					}
+				}
+			);
+		}
+	);
+	
+    var index = GameLib.Utils.GetRandomInt(0, positions.length);
 
-    return {
-        x : x,
-        y : y
-    };
+    return positions[index];
 
 }.bind(this);