diff --git a/src/wp-includes/blocks/index.php b/src/wp-includes/blocks/index.php
index f7382b1e9ae8..755944db03c9 100644
--- a/src/wp-includes/blocks/index.php
+++ b/src/wp-includes/blocks/index.php
@@ -48,6 +48,7 @@
 require ABSPATH . WPINC . '/blocks/tag-cloud.php';
 require ABSPATH . WPINC . '/blocks/template-part.php';
 require ABSPATH . WPINC . '/blocks/term-description.php';
+require ABSPATH . WPINC . '/blocks/widget-group.php';
 
 /**
  * Registers core block types using metadata files.
diff --git a/tests/phpunit/includes/functions.php b/tests/phpunit/includes/functions.php
index 143409606752..909a25cb6be2 100644
--- a/tests/phpunit/includes/functions.php
+++ b/tests/phpunit/includes/functions.php
@@ -346,5 +346,6 @@ function _unhook_block_registration() {
 	remove_action( 'init', 'register_block_core_template_part' );
 	remove_action( 'init', 'register_block_core_term_description' );
 	remove_action( 'init', 'register_core_block_types_from_metadata' );
+	remove_action( 'init', 'register_block_core_widget_group' );
 }
 tests_add_filter( 'init', '_unhook_block_registration', 1000 );