diff --git a/service_container/tags.rst b/service_container/tags.rst
index 0e24af1f57c..1b60653fd56 100644
--- a/service_container/tags.rst
+++ b/service_container/tags.rst
@@ -425,7 +425,7 @@ use this, update the compiler::
                 foreach ($tags as $attributes) {
                     $definition->addMethodCall('addTransport', [
                         new Reference($id),
-                        $attributes["alias"]
+                        $attributes['alias']
                     ]);
                 }
             }