diff -u b/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php b/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php
--- b/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php
@@ -91,7 +91,7 @@
    *   An string|array representing the block. This will be modified to be a
    *   renderable array, containing the optional '#contextual_links' property (if
    *   there are any contextual links associated with the block).
-   * @param $block_type
+   * @param string $block_type
    *   The type of the block. If it's 'block' it's a regular views display,
    *   but 'exposed_filter' exist as well.
    */