diff --git a/dbus_service.h b/dbus_service.h
index 12f8cf1..8b25d43 100644
--- a/dbus_service.h
+++ b/dbus_service.h
@@ -147,8 +147,7 @@
 class UpdateEngineAdaptor : public org::chromium::UpdateEngineInterfaceAdaptor,
                             public ServiceObserverInterface {
  public:
-  UpdateEngineAdaptor(SystemState* system_state,
-                      const scoped_refptr<dbus::Bus>& bus);
+  UpdateEngineAdaptor(SystemState* system_state);
   ~UpdateEngineAdaptor() = default;
 
   // Register the DBus object with the update engine service asynchronously.