diff --git a/src/ol/tilegrid/tilegrid.js b/src/ol/tilegrid/tilegrid.js
index 589b1178f4..859fd62217 100644
--- a/src/ol/tilegrid/tilegrid.js
+++ b/src/ol/tilegrid/tilegrid.js
@@ -116,6 +116,12 @@ ol.tilegrid.TileGrid = function(options) {
    */
   this.fullTileRanges_ = null;
 
+  /**
+   * @private
+   * @type {ol.Size}
+   */
+  this.tmpSize_ = [0, 0];
+
   if (options.sizes !== undefined) {
     goog.asserts.assert(options.sizes.length == this.resolutions_.length,
         'number of sizes and resolutions must be equal');
@@ -136,12 +142,6 @@ ol.tilegrid.TileGrid = function(options) {
     this.calculateTileRanges_(extent);
   }
 
-  /**
-   * @private
-   * @type {ol.Size}
-   */
-  this.tmpSize_ = [0, 0];
-
 };