diff --git a/core/AssetManager/UIAssetMinifier.php b/core/AssetManager/UIAssetMinifier.php
index 83705f7e9c8c85211add9f2189a9c5d123de9447..5391c20e44ba41640194f79bc08b22ac267ae35a 100644
--- a/core/AssetManager/UIAssetMinifier.php
+++ b/core/AssetManager/UIAssetMinifier.php
@@ -61,7 +61,7 @@ class UIAssetMinifier extends Singleton
 
     private static function validateDependency()
     {
-        if (!class_exists("JShrink\Minifier"))
-            throw new Exception("JShrink dependency is managed using Composer. <br> $ php composer.phar update  ");
+        if (!class_exists("JShrink\\Minifier"))
+            throw new Exception("JShrink dependency is managed using Composer. <br>php composer.phar update  ");
     }
 }
diff --git a/core/Filechecks.php b/core/Filechecks.php
index 345ff14c6b45f875a9df51d1bcdb0843c169096a..8d63c7fbf91f10894a128ebf6d816360aabe3e3b 100644
--- a/core/Filechecks.php
+++ b/core/Filechecks.php
@@ -120,7 +120,7 @@ class Filechecks
             require_once $manifest;
         }
 
-        if (!class_exists('\\Piwik\\Manifest')) {
+        if (!class_exists('Piwik\\Manifest')) {
             $git = SettingsPiwik::getCurrentGitBranch();
             if(empty($git)) {
                 $messages[] = Piwik::translate('General_WarningFileIntegrityNoManifest') . " If you are deploying Piwik from Git, this message is normal.";
diff --git a/core/Plugin/Manager.php b/core/Plugin/Manager.php
index f8e72d6610347d64b20cfd787f67b61fc71fe5ed..b85407eeca2b8d898884a0afb219ab7e8b79e5bc 100644
--- a/core/Plugin/Manager.php
+++ b/core/Plugin/Manager.php
@@ -826,7 +826,7 @@ class Manager extends Singleton
     private function loadTranslation($plugin, $langCode)
     {
         // we are in Tracker mode if Loader is not (yet) loaded
-        if (!class_exists('Piwik\Loader', false)) {
+        if (!class_exists('Piwik\\Loader', false)) {
             return false;
         }