diff --git a/DependencyInjection/Configuration.php b/DependencyInjection/Configuration.php
index 4b9cba67..f2e429f5 100644
--- a/DependencyInjection/Configuration.php
+++ b/DependencyInjection/Configuration.php
@@ -78,7 +78,7 @@ protected function addConnections(ArrayNodeDefinition $node)
                                 ->values([
                                     AMQPConnectionConfig::AUTH_AMQPPLAIN,
                                     AMQPConnectionConfig::AUTH_PLAIN,
-                                    AMQPConnectionConfig::AUTH_EXTERNAL
+                                    AMQPConnectionConfig::AUTH_EXTERNAL,
                                 ])
                                 ->defaultValue(AMQPConnectionConfig::AUTH_AMQPPLAIN)
                                 ->end()