diff --git a/cellular_service.cc b/cellular_service.cc
index 2daf880..b7b3b8a 100644
--- a/cellular_service.cc
+++ b/cellular_service.cc
@@ -49,7 +49,7 @@
   cellular_->Connect(error);
 }
 
-void CellularService::Disconnect() { }
+void CellularService::Disconnect(Error */*error*/) { }
 
 void CellularService::ActivateCellularModem(const string &carrier,
                                             Error *error) {