diff --git a/src/Ekreative/RedmineLoginBundle/Security/RedmineSimplePreAuthenticator.php b/src/Ekreative/RedmineLoginBundle/Security/RedmineSimplePreAuthenticator.php
index <HASH>..<HASH> 100644
--- a/src/Ekreative/RedmineLoginBundle/Security/RedmineSimplePreAuthenticator.php
+++ b/src/Ekreative/RedmineLoginBundle/Security/RedmineSimplePreAuthenticator.php
@@ -66,7 +66,7 @@ class RedmineSimplePreAuthenticator implements SimplePreAuthenticatorInterface
         $apiKey = $request->headers->get($this->apiHeader) ?: $request->headers->get('X-Redmine-API-Key');
 
         if (!$apiKey) {
-            throw new BadCredentialsException('No API key found');
+            return null;
         }
 
         return new PreAuthenticatedToken(
Allow both authenticators to work on the same firewall