diff --git a/src/widget.cpp b/src/widget.cpp
index 5c5f3929db..148bd8ddec 100644
--- a/src/widget.cpp
+++ b/src/widget.cpp
@@ -1492,10 +1492,13 @@ NWidgetCore *NWidgetStacked::GetWidgetFromPos(int x, int y)
 /**
  * Select which plane to show (for #NWID_SELECTION only).
  * @param plane Plane number to display.
+ * @return true iff the shown plane changed.
  */
-void NWidgetStacked::SetDisplayedPlane(int plane)
+bool NWidgetStacked::SetDisplayedPlane(int plane)
 {
+	if (this->shown_plane == plane) return false;
 	this->shown_plane = plane;
+	return true;
 }
 
 NWidgetPIPContainer::NWidgetPIPContainer(WidgetType tp, NWidContainerFlags flags) : NWidgetContainer(tp)
diff --git a/src/widget_type.h b/src/widget_type.h
index b1f8cde029..8ec91855c6 100644
--- a/src/widget_type.h
+++ b/src/widget_type.h
@@ -461,7 +461,7 @@ public:
 	void Draw(const Window *w) override;
 	NWidgetCore *GetWidgetFromPos(int x, int y) override;
 
-	void SetDisplayedPlane(int plane);
+	bool SetDisplayedPlane(int plane);
 
 	int shown_plane; ///< Plane being displayed (for #NWID_SELECTION only).
 	int index;       ///< If non-negative, index in the #Window::nested_array.