diff --git a/admin/create-theme/theme-zip.php b/admin/create-theme/theme-zip.php
index 6d37a195..ab5f394b 100644
--- a/admin/create-theme/theme-zip.php
+++ b/admin/create-theme/theme-zip.php
@@ -195,7 +195,7 @@ public static function add_templates_to_zip( $zip, $export_type, $new_slug ) {
 
 			// Write the template content
 			$zip->addFromStringToTheme(
-				$template_folders['wp_template_part'] . '/' . $template->slug . '.html',
+				path_join( $template_folders['wp_template_part'], $template->slug . '.html' ),
 				$template->content
 			);