diff --git a/DependencyInjection/Configuration.php b/DependencyInjection/Configuration.php
index a3fcad1..13b56eb 100644
--- a/DependencyInjection/Configuration.php
+++ b/DependencyInjection/Configuration.php
@@ -36,6 +36,9 @@ public function getConfigTreeBuilder()
                 ->scalarNode('usernameAttribute')
                     ->defaultValue('REMOTE_USER')
                 ->end()
+                ->scalarNode('moduleAttribute')
+                    ->defaultValue('HTTP_SHIB_APPLICATION_ID')
+                ->end()
             ->end()
         ;
         
diff --git a/Security/ShibbolethAuthenticator.php b/Security/ShibbolethAuthenticator.php
index cdba2ae..d809328 100644
--- a/Security/ShibbolethAuthenticator.php
+++ b/Security/ShibbolethAuthenticator.php
@@ -38,10 +38,7 @@ public function __construct($logger, $config, TokenStorage $tokenStorage, Router
     public function getCredentials(Request $request)
     {
         $this->logger->debug('[ShibbolethAuthenticator::getCredential]');
-        $shibbolethModuleAttribute = 'HTTP_SHIB_APPLICATION_ID';
-        if (array_key_exists('moduleAttribute', $this->config)) {
-            $shibbolethModuleAttribute = $this->config['moduleAttribute'];
-        };
+        $shibbolethModuleAttribute = $this->config['moduleAttribute'];
         if ($request->server->has($shibbolethModuleAttribute)) {
             // What you return here will be passed to getUser() as $credentials
             $username = $request->server->get($this->config['usernameAttribute']);