--- a/industry_cmd.c	Wed Oct 19 08:34:37 2005 +0000
+++ b/industry_cmd.c	Wed Oct 19 14:49:46 2005 +0000
@@ -398,8 +398,9 @@
 }
 
 
-static uint GetSlopeZ_Industry(TileInfo *ti) {
-	return GetPartialZ(ti->x&0xF, ti->y&0xF, ti->tileh) + ti->z;
+static uint GetSlopeZ_Industry(const TileInfo* ti)
+{
+	return GetPartialZ(ti->x & 0xF, ti->y & 0xF, ti->tileh) + ti->z;
 }
 
 static uint GetSlopeTileh_Industry(const TileInfo *ti) {