diff --git a/core/scripts/run-tests.sh b/core/scripts/run-tests.sh
index c061be91c9bc6cb5d194c1f518318ee77671e890..6f11827b72e22dd6d994132744e345f168bb05e6 100755
--- a/core/scripts/run-tests.sh
+++ b/core/scripts/run-tests.sh
@@ -1271,7 +1271,7 @@ function simpletest_script_open_browser() {
// Make the html page to write to disk.
$render_service = \Drupal::service('renderer');
- $html = '<head>' . ($js_assets_header) . $render_service->renderPlain($css_assets) . '</head><body>' . $render_service->renderPlain($form) . $render_service->renderPlain($js_assets_footer) .'</body>';
+ $html = '<head>' . $render_service->renderPlain($js_assets_header) . $render_service->renderPlain($css_assets) . '</head><body>' . $render_service->renderPlain($form) . $render_service->renderPlain($js_assets_footer) .'</body>';
// Ensure we have assets verbose directory - tests with no verbose output will not
// have created one.