diff --git a/testing/mochitest/install.rdf b/testing/mochitest/install.rdf
index 9b25eb6d21f..6d758b3bcfe 100644
--- a/testing/mochitest/install.rdf
+++ b/testing/mochitest/install.rdf
@@ -12,7 +12,8 @@
       <Description>
         <em:id>toolkit@mozilla.org</em:id>
 #expand        <em:minVersion>__MOZILLA_VERSION_U__</em:minVersion>
-#expand        <em:maxVersion>__MOZILLA_VERSION_U__</em:maxVersion>
+               <!-- Set to * so toolkit/mozapps/update/chrome tests pass. -->
+               <em:maxVersion>*</em:maxVersion>
       </Description>
     </em:targetApplication>
     <!-- Front End MetaData -->
diff --git a/toolkit/mozapps/update/tests/chrome/utils.js b/toolkit/mozapps/update/tests/chrome/utils.js
index 3da17d2aca5..c8525a947ad 100644
--- a/toolkit/mozapps/update/tests/chrome/utils.js
+++ b/toolkit/mozapps/update/tests/chrome/utils.js
@@ -1295,17 +1295,18 @@ function setupAddons(aCallback) {
   // tests.
   AddonManager.getAllAddons(function(aAddons) {
     let disabledAddons = [];
+    let harnessAddons = ["special-powers@mozilla.org", "mochikit@mozilla.org"];
     aAddons.forEach(function(aAddon) {
       // If an addon's type equals plugin it is skipped since
       // checking plugins compatibility information isn't supported at this
       // time (also see bug 566787). Also, SCOPE_APPLICATION add-ons are
       // excluded by app update so there is no reason to disable them.
-      // Specialpowers is excluded as the test harness requires it to run
-      // the tests.
+      // Specialpowers and mochikit are excluded as the test harness requires
+      // them to run the tests.
       if (aAddon.type != "plugin" && !aAddon.appDisabled &&
           !aAddon.userDisabled &&
           aAddon.scope != AddonManager.SCOPE_APPLICATION &&
-          aAddon.id != "special-powers@mozilla.org") {
+          harnessAddons.indexOf(aAddon.id) == -1) {
         disabledAddons.push(aAddon);
         aAddon.userDisabled = true;
       }