diff --git a/netwerk/test/mochitests/Makefile.in b/netwerk/test/mochitests/Makefile.in
index 5a0ed2ab495a..681212e0dda8 100644
--- a/netwerk/test/mochitests/Makefile.in
+++ b/netwerk/test/mochitests/Makefile.in
@@ -9,6 +9,4 @@ MOCHITEST_FILES = \
   test_partially_cached_content.html \
   user_agent.sjs \
   test_user_agent_overrides.html \
-  user_agent_update.sjs \
-  test_user_agent_updates.html \
   $(NULL)
diff --git a/netwerk/test/mochitests/test_user_agent_updates.html b/netwerk/test/mochitests/test_user_agent_updates.html
deleted file mode 100644
index 83a20e892ae6..000000000000
--- a/netwerk/test/mochitests/test_user_agent_updates.html
+++ /dev/null
@@ -1,221 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<!--
-https://bugzilla.mozilla.org/show_bug.cgi?id=897221
--->
-<head>
-  <title>Test for User Agent Updates</title>
-  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
-  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
-</head>
-<body>
-<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=897221">Mozilla Bug 897221</a>
-<p id="display"></p>
-<div id="content" style="display: none"></div>
-<pre id="test">
-<script class="testbody" type="text/javascript">
-
-const PREF_UPDATES = "general.useragent.updates.";
-const PREF_UPDATES_ENABLED = PREF_UPDATES + "enabled";
-const PREF_UPDATES_URL = PREF_UPDATES + "url";
-const PREF_UPDATES_INTERVAL = PREF_UPDATES + "interval";
-const PREF_UPDATES_TIMEOUT = PREF_UPDATES + "timeout";
-
-const KEY_PREFDIR = "PrefD";
-const KEY_APPDIR = "XCurProcD";
-const FILE_UPDATES = "ua-update.json";
-
-const DEFAULT_UA = navigator.userAgent;
-const UA_OVERRIDE = "DummyUserAgent";
-const UA_ALT_OVERRIDE = "AltUserAgent";
-
-function getUA(host) {
-  var url = location.pathname;
-  url = host + url.slice(0, url.lastIndexOf('/')) + '/user_agent.sjs';
-
-  var xhr = new XMLHttpRequest();
-  xhr.open('GET', url, false); // sync request
-  xhr.send();
-  is(xhr.status, 200, 'request failed');
-  is(typeof xhr.response, 'string', 'invalid response');
-  return xhr.response;
-}
-
-const OVERRIDES = [
-  {
-    domain: 'example.org',
-    override: '%DATE%',
-    host: 'http://example.org'
-  },
-  {
-    domain: 'test1.example.org',
-    override: '%PRODUCT%',
-    expected: SpecialPowers.Services.appinfo.name,
-    host: 'http://test1.example.org'
-  },
-  {
-    domain: 'test2.example.org',
-    override: '%APP_ID%',
-    expected: SpecialPowers.Services.appinfo.ID,
-    host: 'http://test2.example.org'
-  },
-  {
-    domain: 'sub1.test1.example.org',
-    override: '%APP_VERSION%',
-    expected: SpecialPowers.Services.appinfo.version,
-    host: 'http://sub1.test1.example.org'
-  },
-  {
-    domain: 'sub2.test1.example.org',
-    override: '%BUILD_ID%',
-    expected: SpecialPowers.Services.appinfo.appBuildID,
-    host: 'http://sub2.test1.example.org'
-  },
-  {
-    domain: 'sub1.test2.example.org',
-    override: '%OS%',
-    expected: SpecialPowers.Services.appinfo.OS,
-    host: 'http://sub1.test2.example.org'
-  },
-];
-
-function getUpdateURL() {
-  var url = location.pathname;
-  url = location.origin + url.slice(0, url.lastIndexOf('/')) + '/user_agent_update.sjs?';
-
-  var overrides = {};
-  overrides[location.hostname] = UA_OVERRIDE;
-  OVERRIDES.forEach(function (val) {
-    overrides[val.domain] = val.override;
-  });
-  url = url + encodeURIComponent(JSON.stringify(overrides)).replace(/%25/g, '%');
-  return url;
-}
-
-function testDownload(callback) {
-  var startTime = Date.now();
-  var url = getUpdateURL();
-  isnot(navigator.userAgent, UA_OVERRIDE, 'UA already overridden');
-  info('Waiting for UA update: ' + url);
-  SpecialPowers.pushPrefEnv({
-    set: [
-      [PREF_UPDATES_ENABLED, true],
-      [PREF_UPDATES_URL, url],
-      [PREF_UPDATES_TIMEOUT, 10000],
-      [PREF_UPDATES_INTERVAL, 1] // 1 second interval
-    ]
-  }, function waitForUpdate() setTimeout(function () {
-    if (navigator.userAgent !== UA_OVERRIDE) {
-      waitForUpdate();
-      return;
-    }
-    info('Overrode navigator UA');
-    is(getUA(location.origin), UA_OVERRIDE, 'Header UA not overridden');
-
-    var updateTime = parseInt(getUA('http://example.org'));
-    ok(startTime <= updateTime, 'Update was before start time');
-    ok(updateTime <= Date.now(), 'Update was after present time');
-
-    OVERRIDES.forEach(function (val) {
-      val.expected && is(getUA(val.host), val.expected,
-        'Incorrect URL parameter: ' + val.override);
-    });
-    callback();
-  }, 100));
-}
-
-function testProfileLoad(callback) {
-  var file = FU.getFile(KEY_APPDIR, [FILE_UPDATES]).path;
-  var encoder = SpecialPowers.wrap(new TextEncoder());
-  var overrides = {};
-  overrides[location.hostname] = UA_ALT_OVERRIDE;
-  var bytes = encoder.encode(JSON.stringify(overrides));
-  OSF.writeAtomic(file, bytes, {tmpPath: file + ".tmp"}).then(
-    () => {
-      SpecialPowers.pushPrefEnv({
-        set: [[PREF_UPDATES_ENABLED, true]]
-      }, function () {
-        // initialize UserAgentOverrides.jsm and
-        // UserAgentUpdates.jsm and load saved file
-        UAO.init();
-        (function waitForLoad() {
-          if (navigator.userAgent !== UA_ALT_OVERRIDE) {
-            setTimeout(waitForLoad, 100);
-            return;
-          }
-          is(getUA(location.origin), UA_ALT_OVERRIDE, 'Did not apply saved override');
-          saveFilePreviousSize = file.fileSize;
-          callback();
-        })();
-      });
-    },
-    (reason) => {
-      throw reason
-    }
-  );
-}
-
-function testProfileSave(callback) {
-  info('Waiting for saving to profile');
-  var file = FU.getFile(KEY_PREFDIR, [FILE_UPDATES]).path;
-  (function waitForSave() {
-    OSF.exists(file).then(
-      (exists) => {
-        if (!exists) {
-          setTimeout(waitForSave, 100);
-          return;
-        }
-        return OSF.read(file).then(
-          (bytes) => {
-            info('Saved new overrides');
-            var decoder = SpecialPowers.wrap(new TextDecoder());
-            var overrides = JSON.parse(decoder.decode(bytes));
-            is(overrides[location.hostname], UA_OVERRIDE, 'Incorrect saved override');
-            OVERRIDES.forEach(function (val) {
-              val.expected && is(overrides[val.domain], val.expected,
-                'Incorrect saved override: ' + val.override);
-            });
-            callback();
-          }
-        );
-      }
-    ).then(null,
-      (reason) => {
-        throw reason
-      }
-    );
-  })();
-}
-
-SimpleTest.waitForExplicitFinish();
-
-SpecialPowers.Cu.import("resource://gre/modules/FileUtils.jsm", window);
-var FU = SpecialPowers.wrap(FileUtils);
-
-SpecialPowers.Cu.import("resource://gre/modules/osfile.jsm", window);
-var OSF = SpecialPowers.wrap(OS).File;
-
-// Enter update timer manager test mode
-(SpecialPowers.Cc["@mozilla.org/updates/timer-manager;1"].getService(
-  SpecialPowers.Ci.nsIObserver)).observe(null, "utm-test-init", "");
-
-SpecialPowers.Cu.import('resource://gre/modules/UserAgentOverrides.jsm', window);
-var UAO = SpecialPowers.wrap(UserAgentOverrides);
-UAO.uninit();
-
-var saveFilePreviousSize = 0;
-
-// testProfileLoad, testDownload, and testProfileSave must run in this order
-//  because testDownload depends on testProfileLoad to call UAO.init()
-//  and testProfileSave depends on testDownload to save overrides to the profile
-testProfileLoad(function()
-  testDownload(function()
-    testProfileSave(SimpleTest.finish)
-  )
-);
-
-</script>
-</pre>
-</body>
-</html>
-
diff --git a/netwerk/test/mochitests/user_agent_update.sjs b/netwerk/test/mochitests/user_agent_update.sjs
deleted file mode 100644
index 9a0bd700aa34..000000000000
--- a/netwerk/test/mochitests/user_agent_update.sjs
+++ /dev/null
@@ -1,11 +0,0 @@
-
-function handleRequest(request, response)
-{
-  // avoid confusing cache behaviors
-  response.setHeader("Cache-Control", "no-cache", false);
-  response.setHeader("Content-Type", "application/json", false);
-
-  // used by test_user_agent_updates test
-  response.write(decodeURIComponent(request.queryString));
-}
-
