diff --git a/core/modules/block/block.api.php b/core/modules/block/block.api.php
index c889e68..d88b2a6 100644
--- a/core/modules/block/block.api.php
+++ b/core/modules/block/block.api.php
@@ -99,5 +99,20 @@ function hook_block_view_NAME_alter(array &$build, \Drupal\block\BlockInterface
 }
 
 /**
+ * Determines the access to a specific block instance.
+ *
+ * It is called by the access methods of the block plugin system.
+ *
+ * @param \Drupal\block\BlockInterface $block
+ *   The block instance.
+ *
+ *  @see  \Drupal\block\BlockInterface::access()
+ *  @see  \Drupal\block\BlockInterface::blockAccess()
+ */
+function hook_block_access(\Drupal\block\BlockInterface $block) {
+  return FALSE;
+}
+
+/**
  * @} End of "addtogroup hooks".
  */