diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 68b10b3e42..6d0ca95f5a 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1730,6 +1730,9 @@ function drupal_common_theme() {
     'region' => [
       'render element' => 'elements',
     ],
+    'block' => [
+      'render element' => 'elements',
+    ],
     'time' => [
       'variables' => ['timestamp' => NULL, 'text' => NULL, 'attributes' => []],
     ],
diff --git a/core/modules/block/block.module b/core/modules/block/block.module
index ee6a4a11ea..c7af03ff83 100644
--- a/core/modules/block/block.module
+++ b/core/modules/block/block.module
@@ -48,17 +48,6 @@ function block_help($route_name, RouteMatchInterface $route_match) {
   }
 }
 
-/**
- * Implements hook_theme().
- */
-function block_theme() {
-  return [
-    'block' => [
-      'render element' => 'elements',
-    ],
-  ];
-}
-
 /**
  * Implements hook_page_top().
  */