diff --git a/core/modules/aggregator/aggregator.module b/core/modules/aggregator/aggregator.module
index 7171f51..960a32c 100644
--- a/core/modules/aggregator/aggregator.module
+++ b/core/modules/aggregator/aggregator.module
@@ -554,7 +554,7 @@ function aggregator_filter_xss($value) {
 }
 
 /**
- * Implements hook_preprocess_HOOK() for block.tpl.php.
+ * Implements hook_preprocess_HOOK() for block.html.twig.
  */
 function aggregator_preprocess_block(&$variables) {
   if ($variables['block']->module == 'aggregator') {
diff --git a/core/modules/book/book.module b/core/modules/book/book.module
index 26f324e..da1a5a1 100644
--- a/core/modules/book/book.module
+++ b/core/modules/book/book.module
@@ -962,7 +962,7 @@ function _book_link_defaults($nid) {
 }
 
  /**
- * Implements hook_preprocess_HOOK() for block.tpl.php.
+ * Implements hook_preprocess_HOOK() for block.html.twig.
  */
 function book_preprocess_block(&$variables) {
   if ($variables['block']-> module == 'book') {
diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index 8e9400f..92fa347 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -1588,7 +1588,7 @@ function comment_preview(Comment $comment) {
 }
 
 /**
- * Implements hook_preprocess_HOOK() for block.tpl.php.
+ * Implements hook_preprocess_HOOK() for block.html.twig.
  */
 function comment_preprocess_block(&$variables) {
   if ($variables['block']->module == 'comment') {
diff --git a/core/modules/forum/forum.module b/core/modules/forum/forum.module
index 16eadd8..e3a4bf3 100644
--- a/core/modules/forum/forum.module
+++ b/core/modules/forum/forum.module
@@ -956,7 +956,7 @@ function forum_get_topics($tid, $sortby, $forum_per_page) {
 }
 
 /**
- * Implements hook_preprocess_HOOK() for block.tpl.php.
+ * Implements hook_preprocess_HOOK() for block.html.twig.
  */
 function forum_preprocess_block(&$variables) {
   if ($variables['block']->module == 'forum') {
diff --git a/core/modules/help/help.module b/core/modules/help/help.module
index aac8636..ae9e841 100644
--- a/core/modules/help/help.module
+++ b/core/modules/help/help.module
@@ -68,7 +68,7 @@ function help_help($path, $arg) {
 }
 
 /**
- * Implements hook_preprocess_HOOK() for block.tpl.php.
+ * Implements hook_preprocess_HOOK() for block.html.twig.
  */
 function help_preprocess_block(&$variables) {
   if ($variables['block']->id == 'system_help_block') {
diff --git a/core/modules/language/language.module b/core/modules/language/language.module
index 6bbb5a7..b4e9390 100644
--- a/core/modules/language/language.module
+++ b/core/modules/language/language.module
@@ -760,7 +760,7 @@ function language_language_delete($language) {
 }
 
 /**
- * Implements hook_preprocess_HOOK() for block.tpl.php.
+ * Implements hook_preprocess_HOOK() for block.html.twig.
  */
 function language_preprocess_block(&$variables) {
   if ($variables['block']->module == 'language') {
diff --git a/core/modules/menu/menu.module b/core/modules/menu/menu.module
index addca0f..c34ee13 100644
--- a/core/modules/menu/menu.module
+++ b/core/modules/menu/menu.module
@@ -723,7 +723,7 @@ function menu_get_menus($all = TRUE) {
 }
 
 /**
- * Implements hook_preprocess_HOOK() for block.tpl.php.
+ * Implements hook_preprocess_HOOK() for block.html.twig.
  */
 function menu_preprocess_block(&$variables) {
   if ($variables['block']->module == 'menu') {
diff --git a/core/modules/node/node.module b/core/modules/node/node.module
index 36dcfe0..8b21558 100644
--- a/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -1113,7 +1113,7 @@ function node_is_page(EntityInterface $node) {
 }
 
 /**
- * Implements hook_preprocess_HOOK() for block.tpl.php.
+ * Implements hook_preprocess_HOOK() for block.html.twig.
  */
 function node_preprocess_block(&$variables) {
   if ($variables['block']->module == 'node') {
diff --git a/core/modules/shortcut/shortcut.module b/core/modules/shortcut/shortcut.module
index 25a04c7..a333180 100644
--- a/core/modules/shortcut/shortcut.module
+++ b/core/modules/shortcut/shortcut.module
@@ -485,7 +485,7 @@ function shortcut_renderable_links($shortcut_set = NULL) {
 }
 
 /**
- * Implements hook_preprocess_HOOK() for block.tpl.php.
+ * Implements hook_preprocess_HOOK() for block.html.twig.
  */
 function shortcut_preprocess_block(&$variables) {
   if ($variables['block']->module == 'shortcut') {
diff --git a/core/modules/statistics/statistics.module b/core/modules/statistics/statistics.module
index 66842a5..6499e73 100644
--- a/core/modules/statistics/statistics.module
+++ b/core/modules/statistics/statistics.module
@@ -234,7 +234,7 @@ function statistics_update_index() {
 }
 
 /**
- * Implements hook_preprocess_HOOK() for block.tpl.php.
+ * Implements hook_preprocess_HOOK() for block.html.twig.
  */
 function statistics_preprocess_block(&$variables) {
   if ($variables['block']->module == 'statistics') {
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 5a90e3e..da8c029 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -2669,7 +2669,7 @@ function system_user_timezone(&$form, &$form_state) {
 }
 
 /**
- * Implements hook_preprocess_HOOK() for block.tpl.php.
+ * Implements hook_preprocess_HOOK() for block.html.twig.
  */
 function system_preprocess_block(&$variables) {
   switch ($variables['block']->id) {
diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index bdf5862..648472b 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -668,7 +668,7 @@ function user_validate_current_pass(&$form, &$form_state) {
 }
 
 /**
- * Implements hook_preprocess_HOOK() for block.tpl.php.
+ * Implements hook_preprocess_HOOK() for block.html.twig.
  */
 function user_preprocess_block(&$variables) {
   if ($variables['block']->module == 'user') {
diff --git a/core/themes/bartik/template.php b/core/themes/bartik/template.php
index 9a6c8a9..a7f6ad5 100644
--- a/core/themes/bartik/template.php
+++ b/core/themes/bartik/template.php
@@ -111,7 +111,7 @@ function bartik_process_maintenance_page(&$variables) {
 }
 
 /**
- * Implements hook_preprocess_HOOK() for block.tpl.php.
+ * Implements hook_preprocess_HOOK() for block.html.twig.
  */
 function bartik_preprocess_block(&$variables) {
   // In the header and footer regions visually hide block titles.