diff --git a/core/lib/Drupal/Core/Asset/CssCollectionOptimizer.php b/core/lib/Drupal/Core/Asset/CssCollectionOptimizer.php
index 275be49..ea37f75 100644
--- a/core/lib/Drupal/Core/Asset/CssCollectionOptimizer.php
+++ b/core/lib/Drupal/Core/Asset/CssCollectionOptimizer.php
@@ -193,7 +193,7 @@ public function deleteAll() {
         file_unmanaged_delete($uri);
       }
     };
-    file_scan_directory('public://css', '/.*/', array('callback' => $delete_stale));
+    file_scan_directory('public://css', '/.*/', ['callback' => $delete_stale]);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Asset/CssCollectionOptimizerLazy.php b/core/lib/Drupal/Core/Asset/CssCollectionOptimizerLazy.php
index 715e48d..a94fed1 100644
--- a/core/lib/Drupal/Core/Asset/CssCollectionOptimizerLazy.php
+++ b/core/lib/Drupal/Core/Asset/CssCollectionOptimizerLazy.php
@@ -55,7 +55,6 @@ class CssCollectionOptimizerLazy implements AssetCollectionGroupOptimizerInterfa
    */
   protected $state;
 
-
   /**
    * Constructs a CssCollectionOptimizerLazy.
    *
@@ -191,7 +190,7 @@ public function deleteAll() {
         file_unmanaged_delete($uri);
       }
     };
-    file_scan_directory('public://css', '/.*/', array('callback' => $delete_stale));
+    file_scan_directory('public://css', '/.*/', ['callback' => $delete_stale]);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Asset/JsCollectionOptimizer.php b/core/lib/Drupal/Core/Asset/JsCollectionOptimizer.php
index 2fb1bd0..2eb68e2 100644
--- a/core/lib/Drupal/Core/Asset/JsCollectionOptimizer.php
+++ b/core/lib/Drupal/Core/Asset/JsCollectionOptimizer.php
@@ -196,7 +196,7 @@ public function deleteAll() {
         file_unmanaged_delete($uri);
       }
     };
-    file_scan_directory('public://js', '/.*/', array('callback' => $delete_stale));
+    file_scan_directory('public://js', '/.*/', ['callback' => $delete_stale]);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Asset/JsCollectionOptimizerLazy.php b/core/lib/Drupal/Core/Asset/JsCollectionOptimizerLazy.php
index 607d509..4d48e0b 100644
--- a/core/lib/Drupal/Core/Asset/JsCollectionOptimizerLazy.php
+++ b/core/lib/Drupal/Core/Asset/JsCollectionOptimizerLazy.php
@@ -202,7 +202,7 @@ public function deleteAll() {
         file_unmanaged_delete($uri);
       }
     };
-    file_scan_directory('public://js', '/.*/', array('callback' => $delete_stale));
+    file_scan_directory('public://js', '/.*/', ['callback' => $delete_stale]);
   }
 
   /**