diff --git a/src/cheat_func.h b/src/cheat_func.h
index 5c205b04bd..8585a589e2 100644
--- a/src/cheat_func.h
+++ b/src/cheat_func.h
@@ -12,8 +12,6 @@
 
 #include "cheat_type.h"
 
-extern Cheats _cheats;
-
 void ShowCheatWindow();
 
 
diff --git a/src/vehicle_gui.cpp b/src/vehicle_gui.cpp
index ed9d4b6a98..83553cad0f 100644
--- a/src/vehicle_gui.cpp
+++ b/src/vehicle_gui.cpp
@@ -51,8 +51,8 @@
 #include "safeguards.h"
 
 
-std::array<std::array<BaseVehicleListWindow::GroupBy, VEH_COMPANY_END>, VLT_END> _grouping{};
-std::array<Sorting, BaseVehicleListWindow::GB_END> _sorting{};
+static std::array<std::array<BaseVehicleListWindow::GroupBy, VEH_COMPANY_END>, VLT_END> _grouping{};
+static std::array<Sorting, BaseVehicleListWindow::GB_END> _sorting{};
 
 static BaseVehicleListWindow::VehicleIndividualSortFunction VehicleNumberSorter;
 static BaseVehicleListWindow::VehicleIndividualSortFunction VehicleNameSorter;
diff --git a/src/vehicle_gui_base.h b/src/vehicle_gui_base.h
index d7e3cdb388..d1097c499c 100644
--- a/src/vehicle_gui_base.h
+++ b/src/vehicle_gui_base.h
@@ -164,7 +164,4 @@ struct Sorting {
 	Listing train;
 };
 
-extern std::array<std::array<BaseVehicleListWindow::GroupBy, VEH_COMPANY_END>, VLT_END> _grouping;
-extern std::array<Sorting, BaseVehicleListWindow::GB_END> _sorting;
-
 #endif /* VEHICLE_GUI_BASE_H */