diff --git a/src/industry_gui.cpp b/src/industry_gui.cpp
index dcb3280df3..8a9c772df2 100644
--- a/src/industry_gui.cpp
+++ b/src/industry_gui.cpp
@@ -2748,16 +2748,7 @@ struct IndustryCargoesWindow : public Window {
 	{
 		if (!this->IsWidgetLowered(WID_IC_NOTIFY)) return;
 
-		/* Only notify the smallmap window if it exists. In particular, do not
-		 * bring it to the front to prevent messing up any nice layout of the user. */
-		InvalidateWindowClassesData(WC_SMALLMAP, 0);
-
-		/* Notify viewports too. */
-		for (Window *w : Window::IterateFromBack()) {
-			if (w->viewport != nullptr)
-				if (w->viewport->zoom >= ZOOM_LVL_DRAW_MAP && w->viewport->map_type == VPMT_INDUSTRY)
-					w->InvalidateData();
-		}
+		UpdateSmallMapSelectedIndustries();
 	}
 
 	/**
diff --git a/src/smallmap_gui.cpp b/src/smallmap_gui.cpp
index 1026fc3cbc..f4b620abae 100644
--- a/src/smallmap_gui.cpp
+++ b/src/smallmap_gui.cpp
@@ -165,6 +165,32 @@ static bool _smallmap_industry_highlight_state;
 /** For connecting company ID to position in owner list (small map legend) */
 uint _company_to_list_pos[MAX_COMPANIES];
 
+static void NotifyAllViewports(ViewportMapType map_type)
+{
+	for (Window *w : Window::IterateFromBack()) {
+		if (w->viewport != nullptr) {
+			if (w->viewport->zoom >= ZOOM_LVL_DRAW_MAP && w->viewport->map_type == map_type) {
+				ClearViewportLandPixelCache(w->viewport);
+				w->InvalidateData();
+			}
+		}
+	}
+}
+
+void UpdateSmallMapSelectedIndustries()
+{
+	extern std::bitset<NUM_INDUSTRYTYPES> _displayed_industries;
+	for (int i = 0; i != _smallmap_industry_count; i++) {
+		_legend_from_industries[i].show_on_map = _displayed_industries.test(_legend_from_industries[i].type);
+	}
+
+	NotifyAllViewports(VPMT_INDUSTRY);
+
+	/* Only notify the smallmap window if it exists. In particular, do not
+	 * bring it to the front to prevent messing up any nice layout of the user. */
+	InvalidateWindowClassesData(WC_SMALLMAP, 0);
+}
+
 /**
  * Fills an array for the industries legends.
  */
@@ -592,17 +618,6 @@ static inline uint32 GetSmallMapOwnerPixels(TileIndex tile, TileType t)
 	return MKCOLOUR_XXXX(_legend_land_owners[_company_to_list_pos[o]].colour);
 }
 
-static void NotifyAllViewports(ViewportMapType map_type)
-{
-	for (Window *w : Window::IterateFromBack()) {
-		if (w->viewport != nullptr)
-			if (w->viewport->zoom >= ZOOM_LVL_DRAW_MAP && w->viewport->map_type == map_type) {
-				ClearViewportLandPixelCache(w->viewport);
-				w->InvalidateData();
-			}
-	}
-}
-
 /** Vehicle colours in #SMT_VEHICLES mode. Indexed by #VehicleType. */
 static const byte _vehicle_type_colours[6] = {
 	PC_RED, PC_YELLOW, PC_LIGHT_BLUE, PC_WHITE, PC_BLACK, PC_RED
@@ -1571,12 +1586,7 @@ int SmallMapWindow::GetPositionOnLegend(Point pt)
 			break;
 
 		case 0: {
-			extern std::bitset<NUM_INDUSTRYTYPES> _displayed_industries;
 			if (this->map_type != SMT_INDUSTRY) this->SwitchMapType(SMT_INDUSTRY);
-
-			for (int i = 0; i != _smallmap_industry_count; i++) {
-				_legend_from_industries[i].show_on_map = _displayed_industries.test(_legend_from_industries[i].type);
-			}
 			break;
 		}
 
diff --git a/src/smallmap_gui.h b/src/smallmap_gui.h
index c76aecc4cf..5a5e13c9e7 100644
--- a/src/smallmap_gui.h
+++ b/src/smallmap_gui.h
@@ -46,6 +46,7 @@ struct TunnelBridgeToMap {
 };
 typedef std::vector<TunnelBridgeToMap> TunnelBridgeToMapVector;
 
+void UpdateSmallMapSelectedIndustries();
 void BuildIndustriesLegend();
 void ShowSmallMap();
 void BuildLandLegend();