diff --git a/docs/en/authenticators.rst b/docs/en/authenticators.rst
index 14cf234d..dd4f5d76 100644
--- a/docs/en/authenticators.rst
+++ b/docs/en/authenticators.rst
@@ -141,7 +141,7 @@ Add the following to your ``Application`` class::
         // ...
         $service->loadIdentifier('Authentication.JwtSubject');
         $service->loadAuthenticator('Authentication.Jwt', [
-            'secretKey' => file_get_contents(CONFIG . '/jwt.pem'),
+            'secretKey' => file_get_contents(CONFIG . '/jwt.key'),
             'algorithm' => 'RS256',
             'returnPayload' => false
         ]);