diff --git a/wp-includes/class-wp-theme.php b/wp-includes/class-wp-theme.php
index 7c25d07b2c..ee74099766 100644
--- a/wp-includes/class-wp-theme.php
+++ b/wp-includes/class-wp-theme.php
@@ -1576,11 +1576,6 @@ final class WP_Theme implements ArrayAccess {
 	 * @return bool
 	 */
 	public function is_block_theme() {
-		if ( ! did_action( 'setup_theme' ) ) {
-			_doing_it_wrong( __METHOD__, __( 'This method should not be called before themes are set up.' ), '6.8.0' );
-			return false;
-		}
-
 		if ( isset( $this->block_theme ) ) {
 			return $this->block_theme;
 		}
diff --git a/wp-includes/theme.php b/wp-includes/theme.php
index 0a3f7c5d65..b4a71d855a 100644
--- a/wp-includes/theme.php
+++ b/wp-includes/theme.php
@@ -4352,6 +4352,11 @@ function create_initial_theme_features() {
  * @return bool Whether the active theme is a block-based theme or not.
  */
 function wp_is_block_theme() {
+	if ( empty( $GLOBALS['wp_theme_directories'] ) ) {
+		_doing_it_wrong( __FUNCTION__, __( 'This function should not be called before the theme directory is registered.' ), '6.8.0' );
+		return false;
+	}
+
 	return wp_get_theme()->is_block_theme();
 }
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index eb7ce2af40..2ba6f642a5 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.8-beta2-60036';
+$wp_version = '6.8-beta2-60037';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.