diff --git a/src/Cache/MasqueradeCacheContext.php b/src/Cache/MasqueradeCacheContext.php
index d6e6c3e..87796b8 100644
--- a/src/Cache/MasqueradeCacheContext.php
+++ b/src/Cache/MasqueradeCacheContext.php
@@ -30,10 +30,7 @@ class MasqueradeCacheContext extends RequestStackCacheContextBase implements Cac
    * {@inheritdoc}
    */
   public function getContext() {
-    return $this->requestStack
-      ->getCurrentRequest()
-      ->getSession()
-      ->has('masquerading');
+    return !empty($_SESSION['masquerading']) ? '1' : '0';
   }
 
   /**