--- a/src/clear_cmd.cpp	Mon Jul 23 19:24:32 2007 +0000
+++ b/src/clear_cmd.cpp	Mon Jul 23 19:30:36 2007 +0000
@@ -179,7 +179,7 @@
 
 	_error_message = STR_1004_TOO_HIGH;
 
-	if (height > 15) return false;
+	if (height > MAX_TILE_HEIGHT) return false;
 
 	nh = TerraformGetHeightOfTile(ts, tile);
 	if (nh < 0 || height == nh) return false;