diff --git a/src/build_vehicle_gui.cpp b/src/build_vehicle_gui.cpp
--- a/src/build_vehicle_gui.cpp
+++ b/src/build_vehicle_gui.cpp
@@ -54,7 +54,7 @@ uint GetEngineListHeight(VehicleType typ
 	return std::max<uint>(GetCharacterHeight(FS_NORMAL) + WidgetDimensions::scaled.matrix.Vertical(), GetVehicleImageCellSize(type, EIT_PURCHASE).height);
 }
 
-static const NWidgetPart _nested_build_vehicle_widgets[] = {
+static constexpr NWidgetPart _nested_build_vehicle_widgets[] = {
 	NWidget(NWID_HORIZONTAL),
 		NWidget(WWT_CLOSEBOX, COLOUR_GREY),
 		NWidget(WWT_CAPTION, COLOUR_GREY, WID_BV_CAPTION), SetDataTip(STR_JUST_STRING, STR_TOOLTIP_WINDOW_TITLE_DRAG_THIS), SetTextStyle(TC_WHITE),