--- a/waypoint.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/waypoint.c	Wed Dec 27 12:38:02 2006 +0000
@@ -9,6 +9,7 @@
 #include "map.h"
 #include "order.h"
 #include "rail_map.h"
+#include "bridge_map.h"
 #include "saveload.h"
 #include "station.h"
 #include "tile.h"
@@ -206,6 +207,8 @@
 		return_cmd_error(STR_0007_FLAT_LAND_REQUIRED);
 	}
 
+	if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+
 	/* Check if there is an already existing, deleted, waypoint close to us that we can reuse. */
 	wp = FindDeletedWaypointCloseTo(tile);
 	if (wp == NULL) {