diff --git a/testing/mochitest/browser-test.js b/testing/mochitest/browser-test.js
index ea4ec51e5ad..7e0d4d2ac38 100644
--- a/testing/mochitest/browser-test.js
+++ b/testing/mochitest/browser-test.js
@@ -71,11 +71,16 @@ Tester.prototype = {
   },
 
   waitForWindowsState: function Tester_waitForWindowsState(aCallback) {
+    let timedOut = this.currentTest && this.currentTest.timedOut;
+    let baseMsg = timedOut ? "Found a {elt} after previous test timed out"
+                           : this.currentTest ? "Found an unexpected {elt} at the end of test run"
+                                              : "Found an unexpected {elt}";
+
     if (this.currentTest && window.gBrowser && gBrowser.tabs.length > 1) {
       while (gBrowser.tabs.length > 1) {
         let lastTab = gBrowser.tabContainer.lastChild;
-        let msg = "Found an unexpected tab at the end of test run: " +
-                  lastTab.linkedBrowser.currentURI.spec;
+        let msg = baseMsg.replace("{elt}", "tab") +
+                  ": " + lastTab.linkedBrowser.currentURI.spec;
         this.currentTest.addResult(new testResult(false, msg, "", false));
         gBrowser.removeTab(lastTab);
       }
@@ -86,11 +91,9 @@ Tester.prototype = {
     while (windowsEnum.hasMoreElements()) {
       let win = windowsEnum.getNext();
       if (win != window && !win.closed) {
-        let msg = "Found an unexpected browser window";
-        if (this.currentTest) {
-          msg += " at the end of test run";
+        let msg = baseMsg.replace("{elt}", "browser window");
+        if (this.currentTest)
           this.currentTest.addResult(new testResult(false, msg, "", false));
-        }
         else
           this.dumper.dump("TEST-UNEXPECTED-FAIL | (browser-test.js) | " + msg + "\n");
 
@@ -222,6 +225,7 @@ Tester.prototype = {
           return;
         }
         self.currentTest.addResult(new testResult(false, "Timed out", "", false));
+        self.currentTest.timedOut = true;
         self.currentTest.scope.__waitTimer = null;
         self.nextTest();
       }, TIMEOUT_SECONDS * 1000);