diff --git a/browser/devtools/webconsole/test/browser_webconsole_bug_642108_pruneTest.js b/browser/devtools/webconsole/test/browser_webconsole_bug_642108_pruneTest.js
index 9c2299d3509..e269b3e9923 100644
--- a/browser/devtools/webconsole/test/browser_webconsole_bug_642108_pruneTest.js
+++ b/browser/devtools/webconsole/test/browser_webconsole_bug_642108_pruneTest.js
@@ -12,53 +12,45 @@ const TEST_URI = "data:text/html;charset=utf-8,<p>test for bug 642108.";
 const LOG_LIMIT = 20;
 
 function test() {
-  addTab(TEST_URI);
-  browser.addEventListener("load", function onLoad(){
-    browser.removeEventListener("load", onLoad, false);
+  let hud;
+
+  Task.spawn(runner).then(finishTest);
+
+  function* runner() {
+    let {tab} = yield loadTab(TEST_URI);
 
     Services.prefs.setIntPref("devtools.hud.loglimit.cssparser", LOG_LIMIT);
+    Services.prefs.setBoolPref("devtools.webconsole.filter.cssparser", true);
 
     registerCleanupFunction(function() {
       Services.prefs.clearUserPref("devtools.hud.loglimit.cssparser");
+      Services.prefs.clearUserPref("devtools.webconsole.filter.cssparser");
     });
 
-    openConsole(null, testCSSPruning);
-  }, true);
-}
+    hud = yield openConsole(tab);
 
-function populateConsoleRepeats(aHudRef) {
-  for (let i = 0; i < 5; i++) {
-    let node = aHudRef.ui.createMessageNode(CATEGORY_CSS, SEVERITY_WARNING,
-                                            "css log x");
-    aHudRef.ui.outputMessage(CATEGORY_CSS, node);
-  }
-}
+    for (let i = 0; i < 5; i++) {
+      logCSSMessage("css log x");
+    }
 
-function populateConsole(aHudRef) {
-  for (let i = 0; i < LOG_LIMIT + 5; i++) {
-    let node = aHudRef.ui.createMessageNode(CATEGORY_CSS, SEVERITY_WARNING,
-                                            "css log " + i);
-    aHudRef.ui.outputMessage(CATEGORY_CSS, node);
-  }
-}
-
-function testCSSPruning(hudRef) {
-  populateConsoleRepeats(hudRef);
-
-  waitForMessages({
-    webconsole: hudRef,
-    messages: [{
-      text: "css log x",
-      category: CATEGORY_CSS,
-      severity: SEVERITY_WARNING,
-      repeats: 5,
-    }],
-  }).then(() => {
-    populateConsole(hudRef);
-    waitForMessages({
-      webconsole: hudRef,
+    yield waitForMessages({
+      webconsole: hud,
       messages: [{
-        text: "css log 0",
+        text: "css log x",
+        category: CATEGORY_CSS,
+        severity: SEVERITY_WARNING,
+        repeats: 5,
+      }],
+    });
+
+    for (let i = 0; i < LOG_LIMIT + 5; i++) {
+      logCSSMessage("css log " + i);
+    }
+
+    let [result] = yield waitForMessages({
+      webconsole: hud,
+      messages: [{
+        text: "css log 5",
         category: CATEGORY_CSS,
         severity: SEVERITY_WARNING,
       },
@@ -67,23 +59,22 @@ function testCSSPruning(hudRef) {
         category: CATEGORY_CSS,
         severity: SEVERITY_WARNING,
       }],
-    }).then(([result]) => {
-      is(countMessageNodes(), LOG_LIMIT, "number of messages");
-
-      is(Object.keys(hudRef.ui._repeatNodes).length, LOG_LIMIT,
-         "repeated nodes pruned from repeatNodes");
-
-      let msg = [...result.matched][0];
-      let repeats = msg.querySelector(".message-repeats");
-      is(repeats.getAttribute("value"), 1,
-         "repeated nodes pruned from repeatNodes (confirmed)");
-
-      finishTest();
     });
-  });
-}
 
-function countMessageNodes() {
-  let outputNode = HUDService.getHudByWindow(content).outputNode;
-  return outputNode.querySelectorAll(".message").length;
+    is(hud.ui.outputNode.querySelectorAll(".message").length, LOG_LIMIT,
+       "number of messages");
+
+    is(Object.keys(hud.ui._repeatNodes).length, LOG_LIMIT,
+       "repeated nodes pruned from repeatNodes");
+
+    let msg = [...result.matched][0];
+    let repeats = msg.querySelector(".message-repeats");
+    is(repeats.getAttribute("value"), 1,
+       "repeated nodes pruned from repeatNodes (confirmed)");
+  }
+
+  function logCSSMessage(msg) {
+    let node = hud.ui.createMessageNode(CATEGORY_CSS, SEVERITY_WARNING, msg);
+    hud.ui.outputMessage(CATEGORY_CSS, node);
+  }
 }