diff --git a/tests/Tile/UTFGrid.html b/tests/Tile/UTFGrid.html
index a44ad35634..efe06882cd 100644
--- a/tests/Tile/UTFGrid.html
+++ b/tests/Tile/UTFGrid.html
@@ -2,6 +2,21 @@
 <html>
 <head>
   <meta http-equiv="content-type" content="text/html; charset=UTF-8">
+  <script>
+      /**
+      * Because browsers that implement requestAnimationFrame may not execute
+      * animation functions while a window is not displayed (e.g. in a hidden
+      * iframe as in these tests), we mask the native implementations here.  The
+      * native requestAnimationFrame functionality is tested in Util.html and
+      * in PanZoom.html (where a popup is opened before panning).  The panTo tests
+      * here will test the fallback setTimeout implementation for animation.
+      */
+      window.requestAnimationFrame = 
+          window.webkitRequestAnimationFrame =
+          window.mozRequestAnimationFrame =
+          window.oRequestAnimationFrame =
+          window.msRequestAnimationFrame = null;
+  </script>
   <script src="../OLLoader.js"></script>
   <script type="text/javascript">
 
