--- a/src/unmovable_cmd.cpp	Fri Sep 14 22:25:00 2007 +0000
+++ b/src/unmovable_cmd.cpp	Fri Sep 14 22:27:40 2007 +0000
@@ -24,6 +24,7 @@
 #include "table/unmovable_land.h"
 #include "genworld.h"
 #include "bridge.h"
+#include "autoslope.h"
 
 /** Destroy a HQ.
  * During normal gameplay you can only implicitely destroy a HQ when you are
@@ -408,6 +409,10 @@
 	/* Owned land remains unsold */
 	if (IsOwnedLand(tile) && CheckTileOwnership(tile)) return CommandCost();
 
+	if (AutoslopeEnabled() && (IsStatue(tile) || IsCompanyHQ(tile))) {
+		if (!IsSteepSlope(tileh_new) && (z_new + GetSlopeMaxZ(tileh_new) == GetTileMaxZ(tile))) return _price.terraform;
+	}
+
 	return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
 }