diff --git src/wp-includes/class-wp-customize-manager.php src/wp-includes/class-wp-customize-manager.php
index 439e2b5..9a1d411 100644
--- src/wp-includes/class-wp-customize-manager.php
+++ src/wp-includes/class-wp-customize-manager.php
@@ -2274,6 +2274,11 @@ final class WP_Customize_Manager {
 			return new WP_Error( 'changeset_post_save_failure', '', $response );
 		}
 
+		// Ensure that auto-draft posts will get garbage-collected.
+		if ( ! wp_next_scheduled( 'wp_scheduled_auto_draft_delete' ) ) {
+			wp_schedule_event( time(), 'daily', 'wp_scheduled_auto_draft_delete' );
+		}
+
 		return $response;
 	}