diff --git a/js/perf/core.js b/js/perf/core.js
index e963f0c00..091a86a0f 100644
--- a/js/perf/core.js
+++ b/js/perf/core.js
@@ -65,7 +65,7 @@ let WINDOW_CONFIGS = [
     { width: 640, height: 480, alpha: true,  maximized: false, count: 10, metric: 'overviewFps10Alpha' }
 ];
 
-function run() {
+function *run() {
     Scripting.defineScriptEvent("overviewShowStart", "Starting to show the overview");
     Scripting.defineScriptEvent("overviewShowDone", "Overview finished showing");
     Scripting.defineScriptEvent("afterShowHide", "After a show/hide cycle for the overview");
diff --git a/js/perf/hwtest.js b/js/perf/hwtest.js
index 7555a8ab2..cce996671 100644
--- a/js/perf/hwtest.js
+++ b/js/perf/hwtest.js
@@ -89,7 +89,7 @@ function extractBootTimestamp() {
     return result;
 }
 
-function run() {
+function *run() {
     Scripting.defineScriptEvent("desktopShown", "Finished initial animation");
     Scripting.defineScriptEvent("overviewShowStart", "Starting to show the overview");
     Scripting.defineScriptEvent("overviewShowDone", "Overview finished showing");