diff --git a/wp-includes/blocks.php b/wp-includes/blocks.php
index 02114cf4cc..31baf119ff 100644
--- a/wp-includes/blocks.php
+++ b/wp-includes/blocks.php
@@ -749,10 +749,10 @@ function get_dynamic_block_names() {
  * @return array Associative array of `$block_type_name => $position` pairs.
  */
 function get_hooked_blocks( $name, $relative_position = '' ) {
-	$block_types = WP_Block_Type_Registry::get_instance()->get_all_registered();
+	$block_types   = WP_Block_Type_Registry::get_instance()->get_all_registered();
 	$hooked_blocks = array();
 	foreach ( $block_types as $block_type ) {
-		if ( ! property_exists( $block_type, 'block_hooks' ) || ! is_array( $block_type->block_hooks ) ) {
+		if ( ! ( $block_type instanceof WP_Block_Type ) || ! is_array( $block_type->block_hooks ) ) {
 			continue;
 		}
 		foreach ( $block_type->block_hooks as $anchor_block_type => $position ) {
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 7303e9cf58..34dc5d625a 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.4-alpha-56676';
+$wp_version = '6.4-alpha-56677';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.