diff --git a/testing/talos/talos/startup_test/tresize/addon/content/tresize.js b/testing/talos/talos/startup_test/tresize/addon/content/tresize.js
index f15e2840c08..6baf654dcf1 100644
--- a/testing/talos/talos/startup_test/tresize/addon/content/tresize.js
+++ b/testing/talos/talos/startup_test/tresize/addon/content/tresize.js
@@ -16,7 +16,7 @@ var dumpDataSet = false;
 var doneCallback = null;
 
 function painted() {
-  window.gBrowser.removeEventListener("MozAfterPaint", painted, true);
+  window.removeEventListener("MozAfterPaint", painted, true);
   var paintTime = window.performance.now();
   Profiler.pause("resize " + count);
   dataSet[count].end = paintTime;
@@ -26,7 +26,7 @@ function painted() {
 function resizeTest() {
   try {
     windowSize += resizeIncrement;
-    window.gBrowser.addEventListener("MozAfterPaint", painted, true);
+    window.addEventListener("MozAfterPaint", painted, true);
     Profiler.resume("resize " + count);
     dataSet[count] = {'start': window.performance.now()};
     window.resizeTo(windowSize,windowSize);
diff --git a/testing/talos/talos/startup_test/tresize/addon/install.rdf b/testing/talos/talos/startup_test/tresize/addon/install.rdf
index 34b6e8c4ef7..bc37eb46cdc 100644
--- a/testing/talos/talos/startup_test/tresize/addon/install.rdf
+++ b/testing/talos/talos/startup_test/tresize/addon/install.rdf
@@ -17,4 +17,5 @@
 <em:creator>Joel Maher</em:creator>
 <em:description>https://wiki.mozilla.org/Buildbot/Talos/Tests</em:description>
 <em:homepageURL>https://wiki.mozilla.org/Buildbot/Talos/Tests</em:homepageURL>
+<em:multiprocessCompatible>true</em:multiprocessCompatible>
 </Description></RDF>