diff --git a/core/lib/Drupal/Core/StreamWrapper/StreamWrapperManager.php b/core/lib/Drupal/Core/StreamWrapper/StreamWrapperManager.php
index 9ff525b..43532a0 100644
--- a/core/lib/Drupal/Core/StreamWrapper/StreamWrapperManager.php
+++ b/core/lib/Drupal/Core/StreamWrapper/StreamWrapperManager.php
@@ -120,7 +120,10 @@ public function __construct(ModuleHandlerInterface $module_handler) {
    *   $filter are returned.
    */
   public function getWrappers($filter = StreamWrapperInterface::ALL) {
-    if (!isset($this->wrappers[$filter])) {
+    if (isset($this->wrappers[$filter])) {
+      return $this->wrappers[$filter];
+    }
+    else if (isset($this->wrappers[StreamWrapperInterface::ALL])) {
       $this->wrappers[$filter] = array();
       foreach ($this->wrappers[StreamWrapperInterface::ALL] as $scheme => $info) {
         // Bit-wise filter.
@@ -128,9 +131,11 @@ public function getWrappers($filter = StreamWrapperInterface::ALL) {
           $this->wrappers[$filter][$scheme] = $info;
         }
       }
+      return $this->wrappers[$filter];
+    }
+    else {
+      return array();
     }
-
-    return $this->wrappers[$filter];
   }
 
   /**