diff --git a/app/Http/Controllers/UpdateController.php b/app/Http/Controllers/UpdateController.php
index 86e20e46..d09c78f1 100644
--- a/app/Http/Controllers/UpdateController.php
+++ b/app/Http/Controllers/UpdateController.php
@@ -3,11 +3,7 @@
 namespace App\Http\Controllers;
 
 use Log;
-use File;
-use Cache;
-use Storage;
 use Exception;
-use ZipArchive;
 use Illuminate\Support\Arr;
 use Illuminate\Http\Request;
 use Composer\Semver\Comparator;
@@ -15,127 +11,46 @@ use App\Services\PackageManager;
 
 class UpdateController extends Controller
 {
-    /**
-     * Current application version.
-     *
-     * @var string
-     */
     protected $currentVersion;
-
-    /**
-     * Latest application version in update source.
-     *
-     * @var string
-     */
-    protected $latestVersion;
-
-    /**
-     * Where to get information of new application versions.
-     *
-     * @var string
-     */
     protected $updateSource;
-
-    /**
-     * Updates information fetched from update source.
-     *
-     * @var array|null
-     */
-    protected $updateInfo;
-
-    /**
-     * Guzzle HTTP client.
-     *
-     * @var \GuzzleHttp\Client
-     */
     protected $guzzle;
+    protected $error;
+    protected $info = [];
 
     public function __construct(\GuzzleHttp\Client $guzzle)
     {
         $this->updateSource = config('app.update_source');
         $this->currentVersion = config('app.version');
-
         $this->guzzle = $guzzle;
     }
 
     public function showUpdatePage()
     {
         $info = [
-            'latest_version'  => '',
-            'current_version' => $this->currentVersion,
-            'release_note'    => '',
-            'release_url'     => '',
-            'pre_release'     => false,
-            // Fallback to current time
-            'release_time'    => '',
-            'new_version_available' => false,
+            'latest'  => Arr::get($this->getUpdateInfo(), 'latest'),
+            'current' => $this->currentVersion,
         ];
-
-        // If current update source is available
-        if ($this->getUpdateInfo()) {
-            $info['latest_version'] = $this->getUpdateInfo('latest_version');
-
-            $info['new_version_available'] = Comparator::greaterThan(
-                $info['latest_version'],
-                $info['current_version']
-            );
-
-            if ($detail = $this->getReleaseInfo($info['latest_version'])) {
-                $info = array_merge($info, Arr::only($detail, [
-                    'release_note',
-                    'release_url',
-                    'release_time',
-                    'pre_release',
-                ]));
-            } else {
-                // if detailed release info is not given
-                $info['new_version_available'] = false;
-            }
-
-            if (! $info['new_version_available']) {
-                $info['release_time'] = Arr::get($this->getReleaseInfo($this->currentVersion), 'release_time');
-            }
-        }
-
-        $connectivity = true;
-
-        try {
-            $this->guzzle->request('GET', $this->updateSource);
-        } catch (Exception $e) {
-            $connectivity = $e->getMessage();
-        }
-
-        $extra = ['canUpdate' => $info['new_version_available']];
-        return view('admin.update', compact('info', 'connectivity', 'extra'));
+        $error = $this->error;
+        $extra = ['canUpdate' => $this->canUpdate()];
+        return view('admin.update', compact('info', 'error', 'extra'));
     }
 
     public function checkUpdates()
     {
-        return json([
-            'latest' => $this->getUpdateInfo('latest_version'),
-            'available' => $this->newVersionAvailable(),
-        ]);
-    }
-
-    protected function newVersionAvailable()
-    {
-        $latest = $this->getUpdateInfo('latest_version');
-
-        return Comparator::greaterThan($latest, $this->currentVersion) && $this->getReleaseInfo($latest);
+        return json(['available' => $this->canUpdate()]);
     }
 
     public function download(Request $request, PackageManager $package)
     {
-        if (! $this->newVersionAvailable()) {
+        if (! $this->canUpdate()) {
             return json([]);
         }
 
-        $url = $this->getReleaseInfo($this->latestVersion)['release_url'];
-        $path = storage_path('packages/bs_'.$this->latestVersion.'.zip');
+        $path = storage_path('packages/bs_'.$this->info['latest'].'.zip');
         switch ($request->get('action')) {
             case 'download':
                 try {
-                    $package->download($url, $path)->extract(base_path());
+                    $package->download($this->info['url'], $path)->extract(base_path());
                     return json(trans('admin.update.complete'), 0);
                 } catch (Exception $e) {
                     report($e);
@@ -148,36 +63,28 @@ class UpdateController extends Controller
         }
     }
 
-    protected function getUpdateInfo($key = null)
+    protected function getUpdateInfo()
     {
-        if (! $this->updateInfo) {
-            // Add timestamp to control cdn cache
-            $url = starts_with($this->updateSource, 'http')
-                ? $this->updateSource.'?v='.substr(time(), 0, -3)
-                : $this->updateSource;
-
+        $acceptableSpec = 1;
+        if (! $this->info) {
             try {
-                $response = $this->guzzle->request('GET', $url)->getBody();
+                $json = $this->guzzle->request('GET', $this->updateSource)->getBody();
+                $info = json_decode($json, true);
+                if (Arr::get($info, 'spec') == $acceptableSpec) {
+                    $this->info = $info;
+                } else {
+                    $this->error = trans('admin.update.spec');
+                }
             } catch (Exception $e) {
-                Log::error('[CheckingUpdate] Failed to get update information: '.$e->getMessage());
-            }
-
-            if (isset($response)) {
-                $this->updateInfo = json_decode($response, true);
+                $this->error = $e->getMessage();
             }
         }
-
-        $this->latestVersion = Arr::get($this->updateInfo, 'latest_version', $this->currentVersion);
-
-        if (! is_null($key)) {
-            return Arr::get($this->updateInfo, $key);
-        }
-
-        return $this->updateInfo;
+        return $this->info;
     }
 
-    protected function getReleaseInfo($version)
+    protected function canUpdate()
     {
-        return Arr::get($this->getUpdateInfo('releases'), $version);
+        $this->getUpdateInfo();
+        return Comparator::greaterThan(Arr::get($this->info, 'latest'), $this->currentVersion);
     }
 }
diff --git a/resources/lang/en/admin.yml b/resources/lang/en/admin.yml
index 2b695c06..9679a77e 100644
--- a/resources/lang/en/admin.yml
+++ b/resources/lang/en/admin.yml
@@ -105,17 +105,16 @@ update:
 
     up-to-date: Already up-to-date.
     available: New version available.
-    pre-release-warning: This update is a pre-release, please double check before updating.
 
     versions:
       latest: "Latest Version:"
       current: "Current Version:"
 
-    pre-release: You are now using pre-release version.
-
     check-github: <a href=":url" target="_blank" class="el-button pull-right">Check GitHub Releases</a>
     button: Update Now
 
+  spec: Current update source is not supported.
+
   cautions:
     title: Cautions
     text: |
@@ -128,7 +127,7 @@ update:
     size: "Size of package:"
 
   errors:
-    connection: "Unable to access to current update source. Details:"
+    connection: "Unable to access to current update source. Details: :error"
 
 download:
   errors:
diff --git a/resources/lang/zh_CN/admin.yml b/resources/lang/zh_CN/admin.yml
index 7002d175..484f1632 100644
--- a/resources/lang/zh_CN/admin.yml
+++ b/resources/lang/zh_CN/admin.yml
@@ -110,17 +110,16 @@ update:
 
     up-to-date: 已更新至最新版本。
     available: 有更新可用。
-    pre-release-warning: 本次更新为预发布版，请谨慎选择是否更新。
 
     versions:
       latest: 最新版本：
       current: 当前版本：
 
-    pre-release: 当前版本为未发布测试版
-
     check-github: <a href=":url" target="_blank" class="el-button pull-right">查看 GitHub Releases</a>
     button: 马上升级
 
+  spec: 不支持当前的更新源。
+
   cautions:
     title: 注意事项
     text: |
@@ -133,7 +132,7 @@ update:
     size: 更新包大小：
 
   errors:
-    connection: 无法访问当前更新源。详细信息：
+    connection: 无法访问当前更新源。详细信息：:error
 
 download:
   errors:
diff --git a/resources/views/admin/update.blade.php b/resources/views/admin/update.blade.php
index 391ff374..010bf38d 100644
--- a/resources/views/admin/update.blade.php
+++ b/resources/views/admin/update.blade.php
@@ -22,20 +22,20 @@
                         <h3 class="box-title">@lang('admin.update.info.title')</h3>
                     </div><!-- /.box-header -->
                     <div class="box-body">
-                        @if ($info['new_version_available'])
+                        @if ($extra['canUpdate'])
                         <div class="callout callout-info">@lang('admin.update.info.available')</div>
                         <table class="table">
                             <tbody>
                                 <tr>
                                     <td class="key">@lang('admin.update.info.versions.latest')</td>
                                     <td class="value">
-                                        v{{ $info['latest_version'] }}
+                                        v{{ $info['latest'] }}
                                     </td>
                                 </tr>
                                 <tr>
                                     <td class="key">@lang('admin.update.info.versions.current')</td>
                                     <td class="value">
-                                        v{{ $info['current_version'] }}
+                                        v{{ $info['current'] }}
                                     </td>
                                 </tr>
 
@@ -43,10 +43,10 @@
                         </table>
                         @else
 
-                            @if ($connectivity === true)
-                            <div class="callout callout-success">{{ trans('admin.update.info.up-to-date') }}</div>
+                            @if (is_string($error))
+                            <div class="callout callout-danger">{{ trans('admin.update.errors.connection', ['error' => $error]) }}</div>
                             @else
-                            <div class="callout callout-danger">{{ trans('admin.update.errors.connection', ['error' => $connectivity]) }}</div>
+                            <div class="callout callout-success">{{ trans('admin.update.info.up-to-date') }}</div>
                             @endif
 
                         <table class="table">
@@ -54,7 +54,7 @@
                                 <tr>
                                     <td class="key">@lang('admin.update.info.versions.current')</td>
                                     <td class="value">
-                                        v{{ $info['current_version'] }}
+                                        v{{ $info['current'] }}
                                     </td>
                                 </tr>
                             </tbody>
diff --git a/tests/UpdateControllerTest.php b/tests/UpdateControllerTest.php
index 50126a10..33755477 100644
--- a/tests/UpdateControllerTest.php
+++ b/tests/UpdateControllerTest.php
@@ -32,18 +32,20 @@ class UpdateControllerTest extends TestCase
         // Can't connect to update source
         $this->appendToGuzzleQueue([
             new RequestException('Connection Error', new Request('GET', 'whatever')),
-            new RequestException('Connection Error', new Request('GET', 'whatever')),
         ]);
         $this->get('/admin/update')->assertSee(config('app.version'));
 
-        // New version available
-        $time = time();
-        $this->appendToGuzzleQueue(200, [], $this->generateFakeUpdateInfo('8.9.3', false, $time));
-        $this->get('/admin/update')->assertSee(config('app.version'))->assertSee('8.9.3');
+        // Missing `spec` field
+        $this->appendToGuzzleQueue([
+            new Response(200, [], json_encode(['latest' => '8.9.3', 'url' => ''])),
+        ]);
+        $this->get('/admin/update')->assertSee(trans('admin.update.spec'));
 
-        // Now using pre-release version
-        $this->appendToGuzzleQueue(200, [], $this->generateFakeUpdateInfo('0.0.1', false, $time));
-        $this->get('/admin/update');
+        // New version available
+        $this->appendToGuzzleQueue([
+            new Response(200, [], $this->mockFakeUpdateInfo('8.9.3')),
+        ]);
+        $this->get('/admin/update')->assertSee(config('app.version'))->assertSee('8.9.3');
     }
 
     public function testCheckUpdates()
@@ -53,21 +55,12 @@ class UpdateControllerTest extends TestCase
         // Update source is unavailable
         $this->appendToGuzzleQueue([
             new RequestException('Connection Error', new Request('GET', 'whatever')),
-            new RequestException('Connection Error', new Request('GET', 'whatever')),
         ]);
-        $this->getJson('/admin/update/check')
-            ->assertJson([
-                'latest' => null,
-                'available' => false,
-            ]);
+        $this->getJson('/admin/update/check')->assertJson(['available' => false]);
 
         // New version available
-        $this->appendToGuzzleQueue(200, [], $this->generateFakeUpdateInfo('8.9.3', false, time()));
-        $this->getJson('/admin/update/check')
-            ->assertJson([
-                'latest' => '8.9.3',
-                'available' => true,
-            ]);
+        $this->appendToGuzzleQueue(200, [], $this->mockFakeUpdateInfo('8.9.3'));
+        $this->getJson('/admin/update/check')->assertJson(['available' => true]);
     }
 
     public function testDownload()
@@ -80,8 +73,8 @@ class UpdateControllerTest extends TestCase
 
         // Download
         $this->appendToGuzzleQueue([
-            new Response(200, [], $this->generateFakeUpdateInfo('8.9.3')),
-            new Response(200, [], $this->generateFakeUpdateInfo('8.9.3')),
+            new Response(200, [], $this->mockFakeUpdateInfo('8.9.3')),
+            new Response(200, [], $this->mockFakeUpdateInfo('8.9.3')),
         ]);
         app()->instance(PackageManager::class, new Concerns\FakePackageManager(null, true));
         $this->getJson('/admin/update/download?action=download')
@@ -95,7 +88,7 @@ class UpdateControllerTest extends TestCase
             ->assertSee('0');
 
         // Invalid action
-        $this->appendToGuzzleQueue(200, [], $this->generateFakeUpdateInfo('8.9.3'));
+        $this->appendToGuzzleQueue(200, [], $this->mockFakeUpdateInfo('8.9.3'));
         $this->getJson('/admin/update/download?action=no')
             ->assertJson([
                 'errno' => 1,
@@ -103,23 +96,12 @@ class UpdateControllerTest extends TestCase
             ]);
     }
 
-    protected function generateFakeUpdateInfo($version, $preview = false, $time = null)
+    protected function mockFakeUpdateInfo($version)
     {
-        $time = $time ?: time();
-
         return json_encode([
-            'app_name' => 'blessing-skin-server',
-            'latest_version' => $version,
-            'update_time' => $time,
-            'releases' => [
-                $version => [
-                    'version' => $version,
-                    'pre_release' => $preview,
-                    'release_time' => $time,
-                    'release_note' => 'test',
-                    'release_url' => "https://whatever.test/$version/update.zip",
-                ],
-            ],
+            'spec' => 1,
+            'latest' => $version,
+            'url' => "https://whatever.test/$version/update.zip",
         ]);
     }
 }