diff --git a/apps/settings/lib/SetupChecks/JavaScriptModules.php b/apps/settings/lib/SetupChecks/JavaScriptModules.php
index 151e04ecf2bf4..30883a5f5f3e7 100644
--- a/apps/settings/lib/SetupChecks/JavaScriptModules.php
+++ b/apps/settings/lib/SetupChecks/JavaScriptModules.php
@@ -64,12 +64,18 @@ public function run(): SetupResult {
 		foreach ($testURLs as $testURL) {
 			try {
 				$client = $this->clientService->newClient();
-				$response = $client->head($testURL, ['connect_timeout' => 10]);
+				$response = $client->head($testURL, [
+						'connect_timeout' => 10,
+						'nextcloud' => [
+							'allow_local_address' => true,
+						],
+					]);
 				if (preg_match('/(text|application)\/javascript/i', $response->getHeader('Content-Type'))) {
 					return SetupResult::success();
 				}
 			} catch (\Throwable $e) {
 				$this->logger->debug('Can not connect to local server for checking JavaScript modules support', ['exception' => $e, 'url' => $testURL]);
+				return SetupResult::warning($this->l10n->t('Could not check for JavaScript support. Please check manually if your webserver serves `.mjs` files using the JavaScript MIME type.'));
 			}
 		}
 		return SetupResult::error($this->l10n->t('Your webserver does not serve `.mjs` files using the JavaScript MIME type. This will break some apps by preventing browsers from executing the JavaScript files. You should configure your webserver to serve `.mjs` files with either the `text/javascript` or `application/javascript` MIME type.'));