diff --git a/newscoop/library/Newscoop/Cache/CacheKey.php b/newscoop/library/Newscoop/Cache/CacheKey.php
new file mode 100644
index 0000000000..2ade971cf4
--- /dev/null
+++ b/newscoop/library/Newscoop/Cache/CacheKey.php
@@ -0,0 +1,22 @@
+<?php
+/**
+ * @package Newscoop
+ * @copyright 2015 Sourcefabric o.p.s.
+ * @author Paweł Mikołąjczuk <pawel.mikolajczuk@sourcefabric.org>
+ * @license http://www.gnu.org/licenses/gpl-3.0.txt
+ */
+
+namespace Newscoop;
+
+/**
+ * Cache key
+ */
+class CacheKey extends ValueObject
+{
+    public $key;
+
+    public function __toString()
+    {
+        return $this->key;
+    }
+}
diff --git a/newscoop/library/Newscoop/Services/CacheService.php b/newscoop/library/Newscoop/Services/CacheService.php
index b3bfd7b778..3fa0a23528 100644
--- a/newscoop/library/Newscoop/Services/CacheService.php
+++ b/newscoop/library/Newscoop/Services/CacheService.php
@@ -8,6 +8,8 @@
 
 namespace Newscoop\Services;
 
+use Newscoop\CacheKey;
+
 /**
  * Cache service
  */
@@ -87,12 +89,16 @@ public function delete($id)
 
     public function getCacheKey($id, $namespace = null)
     {
+        if (is_a($id, 'Newscoop\CacheKey')) {
+            return $id->key;
+        }
+
         if (is_array($id)) {
             $id = implode('__', $id);
         }
 
         // make cache key short
-        $id = base64_encode($id);
+        $id = base64_encode($id.'|'.$this->systemPreferences->installation_id);
 
         if ($namespace) {
             $namespace = $this->getNamespace($namespace);
@@ -100,7 +106,7 @@ public function getCacheKey($id, $namespace = null)
             return $namespace.'__'.$id;
         }
 
-        return $id;
+        return new CacheKey(array('key' => $id));
     }
 
     public function getNamespace($namespace)
@@ -109,7 +115,7 @@ public function getNamespace($namespace)
             return $this->getCacheDriver()->fetch($namespace);
         }
 
-        $value = $namespace .'|'.time();
+        $value = $namespace .'|'.time().'|'.$this->systemPreferences->installation_id;
         $this->getCacheDriver()->save($namespace, $value);
 
         return $value;
diff --git a/newscoop/src/Newscoop/NewscoopBundle/Controller/BackendJournalistDashboardController.php b/newscoop/src/Newscoop/NewscoopBundle/Controller/BackendJournalistDashboardController.php
index d53c487d7d..cdbc398e5e 100644
--- a/newscoop/src/Newscoop/NewscoopBundle/Controller/BackendJournalistDashboardController.php
+++ b/newscoop/src/Newscoop/NewscoopBundle/Controller/BackendJournalistDashboardController.php
@@ -89,7 +89,7 @@ public function loadUsersAction(Request $request)
         }
 
         $criteria = $this->getCriteria($request);
-        $cacheKey = array('author_articles__'.md5(serialize($criteria)), $author->getId());
+        $cacheKey = $cacheService->getCacheKey(array('author_articles__'.md5(serialize($criteria)), $author->getId()));
 
         if ($cacheService->contains($cacheKey)) {
             $responseArray =  $cacheService->fetch($cacheKey);
diff --git a/newscoop/src/Newscoop/NewscoopBundle/Controller/UsersController.php b/newscoop/src/Newscoop/NewscoopBundle/Controller/UsersController.php
index 05c5911fe7..c99f42f18c 100644
--- a/newscoop/src/Newscoop/NewscoopBundle/Controller/UsersController.php
+++ b/newscoop/src/Newscoop/NewscoopBundle/Controller/UsersController.php
@@ -70,7 +70,7 @@ public function loadUsersAction(Request $request)
         $registered = $userService->countBy(array('status' => User::STATUS_ACTIVE));
         $pending = $userService->countBy(array('status' => User::STATUS_INACTIVE));
 
-        $cacheKey = array('users__'.md5(serialize($criteria)), $registered, $pending);
+        $cacheKey = $cacheService->getCacheKey(array('users__'.md5(serialize($criteria)), $registered, $pending));
 
         if ($cacheService->contains($cacheKey)) {
             $responseArray =  $cacheService->fetch($cacheKey);
diff --git a/newscoop/src/Newscoop/NewscoopBundle/EventListener/OldPluginsTranslationListener.php b/newscoop/src/Newscoop/NewscoopBundle/EventListener/OldPluginsTranslationListener.php
index 63431bce6c..e256d89307 100644
--- a/newscoop/src/Newscoop/NewscoopBundle/EventListener/OldPluginsTranslationListener.php
+++ b/newscoop/src/Newscoop/NewscoopBundle/EventListener/OldPluginsTranslationListener.php
@@ -43,7 +43,7 @@ public function onRequest(GetResponseEvent $event)
         }
 
         $locale = $event->getRequest()->getLocale();
-        $cacheKey = 'oldPlugins_translations_'.count($this->pluginsService->getEnabledPlugins());
+        $cacheKey = $cacheService->getCacheKey('oldPlugins_translations_'.count($this->pluginsService->getEnabledPlugins()));
         if ($this->cacheService->contains($cacheKey)) {
             $files = $this->cacheService->fetch($cacheKey);
         } else {