diff --git a/browser/components/sessionstore/test/browser/browser_526613.js b/browser/components/sessionstore/test/browser/browser_526613.js
index 0a220ee24670..4abde379ca3e 100644
--- a/browser/components/sessionstore/test/browser/browser_526613.js
+++ b/browser/components/sessionstore/test/browser/browser_526613.js
@@ -111,6 +111,7 @@ function test() {
         setTimeout(pollMostRecentWindow, 0);
       }
     }
+    window.focus(); //XXX Why is this needed?
     pollMostRecentWindow();
   });
 }