--- a/devtools/client/webconsole/test/browser_webconsole_bug_613642_prune_scroll.js
+++ b/devtools/client/webconsole/test/browser_webconsole_bug_613642_prune_scroll.js
@@ -50,17 +50,19 @@ add_task(function* () {
   msgNode.scrollIntoView(false);
 
   isnot(scrollBoxElement.scrollTop, oldScrollTop,
         "scroll location updated (scrolled to message)");
 
   oldScrollTop = scrollBoxElement.scrollTop;
 
   // add a message
-  content.console.log("hello world");
+  ContentTask.spawn(gBrowser.selectedBrowser, {}, function* () {
+    content.console.log("hello world");
+  });
 
   yield waitForMessages({
     webconsole: hud,
     messages: [{
       text: "hello world",
       category: CATEGORY_WEBDEV,
       severity: SEVERITY_LOG,
     }],