diff --git a/core/modules/block/lib/Drupal/block/BlockBase.php b/core/modules/block/lib/Drupal/block/BlockBase.php
index d32444f..cf30661 100644
--- a/core/modules/block/lib/Drupal/block/BlockBase.php
+++ b/core/modules/block/lib/Drupal/block/BlockBase.php
@@ -10,6 +10,7 @@
 use Drupal\Component\Plugin\PluginBase;
 use Drupal\block\Plugin\Core\Entity\Block;
 use Drupal\Component\Plugin\Discovery\DiscoveryInterface;
+use Drupal\user\Plugin\Core\Entity\User;
 
 /**
  * Defines a base block implementation that most blocks plugins will extend.
@@ -131,7 +132,7 @@ public function blockAccess() {
    * @see hook_block_access()
    * @see \Drupal\block\BlockBase::blockAccess()
    */
-  public function access() {
+  public function access(User $user = NULL) {
     // If the block-specific access restrictions indicate the block is not
     // accessible, always deny access.
     if (!$this->blockAccess()) {
@@ -139,7 +140,11 @@ public function access() {
     }
 
     // Otherwise, check for other access restrictions.
-    global $user;
+    if (!$user) {
+      // For consistency, load actual User entity.
+      // $GLOBALS['user'] is a stdClass.
+      $user = user_load($GLOBALS['user']->uid);
+    }
 
     // Deny access to disabled blocks.
     if (!$this->entity->get('status')) {
diff --git a/core/modules/block/lib/Drupal/block/BlockInterface.php b/core/modules/block/lib/Drupal/block/BlockInterface.php
index 65bdee3..6a89327 100644
--- a/core/modules/block/lib/Drupal/block/BlockInterface.php
+++ b/core/modules/block/lib/Drupal/block/BlockInterface.php
@@ -7,6 +7,8 @@
 
 namespace Drupal\block;
 
+use Drupal\user\Plugin\Core\Entity\User;
+
 /**
  * Defines the required interface for all block plugins.
  *
@@ -37,12 +39,15 @@ public function settings();
    * This method allows base implementations to add general access restrictions
    * that should apply to all extending block plugins.
    *
+   * @param \Drupal\user\Plugin\Core\Entity\User $user
+   *   (optional) User entity to check access for. Defaults to current user.
+   *
    * @return bool
    *   TRUE if the block should be shown, or FALSE otherwise.
    *
    * @see \Drupal\block\BlockAccessController
    */
-  public function access();
+  public function access(User $user = NULL);
 
   /**
    * Constructs the block configuration form.