diff --git a/src/vehicle_gui.cpp b/src/vehicle_gui.cpp
--- a/src/vehicle_gui.cpp
+++ b/src/vehicle_gui.cpp
@@ -868,7 +868,7 @@ struct RefitWindow : public Window {
 		this->DrawWidgets();
 	}
 
-	void UpdateWidgetSize(int widget, Dimension *size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension *fill, [[maybe_unused]] Dimension *resize) override
+	void UpdateWidgetSize(WidgetID widget, Dimension *size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension *fill, [[maybe_unused]] Dimension *resize) override
 	{
 		switch (widget) {
 			case WID_VR_MATRIX:
@@ -886,7 +886,7 @@ struct RefitWindow : public Window {
 		}
 	}
 
-	void SetStringParameters(int widget) const override
+	void SetStringParameters(WidgetID widget) const override
 	{
 		if (widget == WID_VR_CAPTION) SetDParam(0, Vehicle::Get(this->window_number)->index);
 	}
@@ -936,7 +936,7 @@ struct RefitWindow : public Window {
 		}
 	}
 
-	void DrawWidget(const Rect &r, int widget) const override
+	void DrawWidget(const Rect &r, WidgetID widget) const override
 	{
 		switch (widget) {
 			case WID_VR_VEHICLE_PANEL_DISPLAY: {
@@ -1131,7 +1131,7 @@ struct RefitWindow : public Window {
 		}
 	}
 
-	void OnClick([[maybe_unused]] Point pt, int widget, [[maybe_unused]] int click_count) override
+	void OnClick([[maybe_unused]] Point pt, WidgetID widget, [[maybe_unused]] int click_count) override
 	{
 		switch (widget) {
 			case WID_VR_VEHICLE_PANEL_DISPLAY: { // Vehicle image.
@@ -1173,7 +1173,7 @@ struct RefitWindow : public Window {
 		}
 	}
 
-	void OnMouseDrag(Point pt, int widget) override
+	void OnMouseDrag(Point pt, WidgetID widget) override
 	{
 		switch (widget) {
 			case WID_VR_VEHICLE_PANEL_DISPLAY: { // Vehicle image.
@@ -1186,7 +1186,7 @@ struct RefitWindow : public Window {
 		}
 	}
 
-	void OnDragDrop(Point pt, int widget) override
+	void OnDragDrop(Point pt, WidgetID widget) override
 	{
 		switch (widget) {
 			case WID_VR_VEHICLE_PANEL_DISPLAY: { // Vehicle image.
@@ -1853,7 +1853,7 @@ public:
 		*this->sorting = this->vehgroups.GetListing();
 	}
 
-	void UpdateWidgetSize(int widget, Dimension *size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension *fill, [[maybe_unused]] Dimension *resize) override
+	void UpdateWidgetSize(WidgetID widget, Dimension *size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension *fill, [[maybe_unused]] Dimension *resize) override
 	{
 		switch (widget) {
 			case WID_VL_LIST:
@@ -1904,7 +1904,7 @@ public:
 		}
 	}
 
-	void SetStringParameters(int widget) const override
+	void SetStringParameters(WidgetID widget) const override
 	{
 		switch (widget) {
 			case WID_VL_AVAILABLE_VEHICLES:
@@ -1947,7 +1947,7 @@ public:
 		}
 	}
 
-	void DrawWidget(const Rect &r, int widget) const override
+	void DrawWidget(const Rect &r, WidgetID widget) const override
 	{
 		switch (widget) {
 			case WID_VL_SORT_ORDER:
@@ -1997,7 +1997,7 @@ public:
 		this->DrawWidgets();
 	}
 
-	void OnClick([[maybe_unused]] Point pt, int widget, [[maybe_unused]] int click_count) override
+	void OnClick([[maybe_unused]] Point pt, WidgetID widget, [[maybe_unused]] int click_count) override
 	{
 		switch (widget) {
 		    case WID_VL_ORDER_VIEW: // Open the shared orders window
@@ -2081,7 +2081,7 @@ public:
 		}
 	}
 
-	void OnDropdownSelect(int widget, int index) override
+	void OnDropdownSelect(WidgetID widget, int index) override
 	{
 		switch (widget) {
 			case WID_VL_GROUP_BY_PULLDOWN:
@@ -2367,7 +2367,7 @@ struct VehicleDetailsWindow : Window {
 		return desired_height;
 	}
 
-	void UpdateWidgetSize(int widget, Dimension *size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension *fill, [[maybe_unused]] Dimension *resize) override
+	void UpdateWidgetSize(WidgetID widget, Dimension *size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension *fill, [[maybe_unused]] Dimension *resize) override
 	{
 		switch (widget) {
 			case WID_VD_TOP_DETAILS: {
@@ -2474,12 +2474,12 @@ struct VehicleDetailsWindow : Window {
 		}
 	}
 
-	void SetStringParameters(int widget) const override
+	void SetStringParameters(WidgetID widget) const override
 	{
 		if (widget == WID_VD_CAPTION) SetDParam(0, Vehicle::Get(this->window_number)->index);
 	}
 
-	void DrawWidget(const Rect &r, int widget) const override
+	void DrawWidget(const Rect &r, WidgetID widget) const override
 	{
 		const Vehicle *v = Vehicle::Get(this->window_number);
 
@@ -2604,7 +2604,7 @@ struct VehicleDetailsWindow : Window {
 		this->DrawWidgets();
 	}
 
-	void OnClick([[maybe_unused]] Point pt, int widget, [[maybe_unused]] int click_count) override
+	void OnClick([[maybe_unused]] Point pt, WidgetID widget, [[maybe_unused]] int click_count) override
 	{
 		switch (widget) {
 			case WID_VD_INCREASE_SERVICING_INTERVAL:   // increase int
@@ -2642,7 +2642,7 @@ struct VehicleDetailsWindow : Window {
 		}
 	}
 
-	void OnDropdownSelect(int widget, int index) override
+	void OnDropdownSelect(WidgetID widget, int index) override
 	{
 		switch (widget) {
 			case WID_VD_SERVICE_INTERVAL_DROPDOWN: {
@@ -2927,7 +2927,7 @@ public:
 		this->Window::Close();
 	}
 
-	void UpdateWidgetSize(int widget, Dimension *size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension *fill, [[maybe_unused]] Dimension *resize) override
+	void UpdateWidgetSize(WidgetID widget, Dimension *size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension *fill, [[maybe_unused]] Dimension *resize) override
 	{
 		const Vehicle *v = Vehicle::Get(this->window_number);
 		switch (widget) {
@@ -2974,7 +2974,7 @@ public:
 		this->DrawWidgets();
 	}
 
-	void SetStringParameters(int widget) const override
+	void SetStringParameters(WidgetID widget) const override
 	{
 		if (widget != WID_VV_CAPTION) return;
 
@@ -2982,7 +2982,7 @@ public:
 		SetDParam(0, v->index);
 	}
 
-	void DrawWidget(const Rect &r, int widget) const override
+	void DrawWidget(const Rect &r, WidgetID widget) const override
 	{
 		if (widget != WID_VV_START_STOP) return;
 
@@ -3087,7 +3087,7 @@ public:
 		DrawString(tr.left, tr.right, CenterBounds(tr.top, tr.bottom, GetCharacterHeight(FS_NORMAL)), str, text_colour, SA_HOR_CENTER);
 	}
 
-	void OnClick([[maybe_unused]] Point pt, int widget, [[maybe_unused]] int click_count) override
+	void OnClick([[maybe_unused]] Point pt, WidgetID widget, [[maybe_unused]] int click_count) override
 	{
 		const Vehicle *v = Vehicle::Get(this->window_number);
 
@@ -3195,7 +3195,7 @@ public:
 		Command<CMD_RENAME_VEHICLE>::Post(STR_ERROR_CAN_T_RENAME_TRAIN + Vehicle::Get(this->window_number)->type, this->window_number, str);
 	}
 
-	void OnMouseOver([[maybe_unused]] Point pt, int widget) override
+	void OnMouseOver([[maybe_unused]] Point pt, WidgetID widget) override
 	{
 		bool start_stop = widget == WID_VV_START_STOP;
 		if (start_stop != mouse_over_start_stop) {