diff --git a/DependencyInjection/BeSimpleSoapExtension.php b/DependencyInjection/BeSimpleSoapExtension.php
index a2840ba..b129e12 100644
--- a/DependencyInjection/BeSimpleSoapExtension.php
+++ b/DependencyInjection/BeSimpleSoapExtension.php
@@ -89,12 +89,12 @@ class BeSimpleSoapExtension extends Extension
 
                 $defOptions = $container
                     ->getDefinition('besimple.soap.client')
-                    ->getArgument(1);
+                    ->getArgument(2);
 
                 $defOptions['cache_type'] = $options['cache_type'];
                 $defOptions['namespace']  = $options['namespace'];
 
-                $definition->replaceArgument(1, $defOptions);
+                $definition->replaceArgument(2, $defOptions);
             }
         }
     }
diff --git a/Resources/config/client.xml b/Resources/config/client.xml
index 8ef5918..741bfc1 100644
--- a/Resources/config/client.xml
+++ b/Resources/config/client.xml
@@ -10,6 +10,7 @@
     <services>
         <service id="besimple.soap.client" class="%besimple.soap.client.class%" abstract="true">
             <argument>wsdl</argument>
+            <argument>null</argument>
             <argument type="collection">
                 <argument key="debug">%kernel.debug%</argument>
                 <argument key="cache_type">null</argument>