diff --git a/src/airport_gui.cpp b/src/airport_gui.cpp
--- a/src/airport_gui.cpp
+++ b/src/airport_gui.cpp
@@ -90,7 +90,7 @@ struct BuildAirToolbarWindow : Window {
 		this->last_user_action = INVALID_WID_AT;
 	}
 
-	void Close() override
+	void Close([[maybe_unused]] int data = 0) override
 	{
 		if (this->IsWidgetLowered(WID_AT_AIRPORT)) SetViewportCatchmentStation(nullptr, true);
 		if (_settings_client.gui.link_terraform_toolbar) CloseWindowById(WC_SCEN_LAND_GEN, 0, false);
@@ -285,7 +285,7 @@ public:
 		if (selectFirstAirport) this->SelectFirstAvailableAirport(true);
 	}
 
-	void Close() override
+	void Close([[maybe_unused]] int data = 0) override
 	{
 		CloseWindowById(WC_SELECT_STATION, 0);
 		this->PickerWindowBase::Close();