diff --git a/src/rail_gui.cpp b/src/rail_gui.cpp
index ba4256c945..6b1e9f61c0 100644
--- a/src/rail_gui.cpp
+++ b/src/rail_gui.cpp
@@ -2277,7 +2277,7 @@ struct BuildRailWaypointWindow : PickerWindowBase {
 		this->FinishInitNested(TRANSPORT_RAIL);
 
 		matrix->SetCount(_waypoint_count);
-		matrix->SetClicked(_cur_waypoint_type);
+		matrix->SetClicked(_cur_waypoint_type < _waypoint_count ? _cur_waypoint_type : 0);
 	}
 
 	void UpdateWidgetSize(int widget, Dimension *size, const Dimension &padding, Dimension *fill, Dimension *resize) override