diff --git a/wp-includes/blocks.php b/wp-includes/blocks.php
index 838cd84a19..8472c7e092 100644
--- a/wp-includes/blocks.php
+++ b/wp-includes/blocks.php
@@ -328,8 +328,9 @@ function register_block_style_handle( $metadata, $field_name, $index = 0 ) {
 	$style_path_norm = wp_normalize_path( realpath( dirname( $metadata['file'] ) . '/' . $style_path ) );
 	$style_uri       = get_block_asset_url( $style_path_norm );
 
-	$version = ! $is_core_block && isset( $metadata['version'] ) ? $metadata['version'] : false;
-	$result  = wp_register_style(
+	$block_version = ! $is_core_block && isset( $metadata['version'] ) ? $metadata['version'] : false;
+	$version       = $style_path_norm && defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG ? filemtime( $style_path_norm ) : $block_version;
+	$result        = wp_register_style(
 		$style_handle_name,
 		$style_uri,
 		array(),
diff --git a/wp-includes/version.php b/wp-includes/version.php
index e2932aa5d2..3130973e27 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.8.2-alpha-60433';
+$wp_version = '6.8.2-alpha-60434';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.