diff --git a/src/widgets/industry_widget.h b/src/widgets/industry_widget.h
--- a/src/widgets/industry_widget.h
+++ b/src/widgets/industry_widget.h
@@ -11,7 +11,7 @@
 #define WIDGETS_INDUSTRY_WIDGET_H
 
 /** Widgets of the #BuildIndustryWindow class. */
-enum DynamicPlaceIndustriesWidgets {
+enum DynamicPlaceIndustriesWidgets : WidgetID {
 	WID_DPI_SCENARIO_EDITOR_PANE,            ///< Pane containing SE-only widgets.
 	WID_DPI_REMOVE_ALL_INDUSTRIES_WIDGET,    ///< Remove all industries button.
 	WID_DPI_CREATE_RANDOM_INDUSTRIES_WIDGET, ///< Create random industries button.
@@ -23,7 +23,7 @@ enum DynamicPlaceIndustriesWidgets {
 };
 
 /** Widgets of the #IndustryViewWindow class. */
-enum IndustryViewWidgets {
+enum IndustryViewWidgets : WidgetID {
 	WID_IV_CAPTION,  ///< Caption of the window.
 	WID_IV_VIEWPORT, ///< Viewport of the industry.
 	WID_IV_INFO,     ///< Info of the industry.
@@ -32,7 +32,7 @@ enum IndustryViewWidgets {
 };
 
 /** Widgets of the #IndustryDirectoryWindow class. */
-enum IndustryDirectoryWidgets {
+enum IndustryDirectoryWidgets : WidgetID {
 	WID_ID_DROPDOWN_ORDER,       ///< Dropdown for the order of the sort.
 	WID_ID_DROPDOWN_CRITERIA,    ///< Dropdown for the criteria of the sort.
 	WID_ID_FILTER_BY_ACC_CARGO,  ///< Accepted cargo filter dropdown list.
@@ -44,7 +44,7 @@ enum IndustryDirectoryWidgets {
 };
 
 /** Widgets of the #IndustryCargoesWindow class */
-enum IndustryCargoesWidgets {
+enum IndustryCargoesWidgets : WidgetID {
 	WID_IC_CAPTION,        ///< Caption of the window.
 	WID_IC_NOTIFY,         ///< Row of buttons at the bottom.
 	WID_IC_PANEL,          ///< Panel that shows the chain.