diff --git a/src/engine_gui.h b/src/engine_gui.h
--- a/src/engine_gui.h
+++ b/src/engine_gui.h
@@ -22,6 +22,11 @@ void EngList_SortPartial(GUIEngineList *
 
 StringID GetEngineCategoryName(EngineID engine);
 StringID GetEngineInfoString(EngineID engine);
-void DrawVehicleEngine(int x, int y, EngineID engine, SpriteID pal);
+
+void DrawVehicleEngine(int left, int right, int preferred_x, int y, EngineID engine, SpriteID pal);
+void DrawTrainEngine(int left, int right, int preferred_x, int y, EngineID engine, SpriteID pal);
+void DrawRoadVehEngine(int left, int right, int preferred_x, int y, EngineID engine, SpriteID pal);
+void DrawShipEngine(int left, int right, int preferred_x, int y, EngineID engine, SpriteID pal);
+void DrawAircraftEngine(int left, int right, int preferred_x, int y, EngineID engine, SpriteID pal);
 
 #endif /* ENGINE_GUI_H */