--- a/src/rail_cmd.cpp	Wed Apr 04 14:21:46 2007 +0000
+++ b/src/rail_cmd.cpp	Thu Apr 05 07:49:04 2007 +0000
@@ -1373,7 +1373,7 @@
 				image += relocation;
 			}
 
-			if (_display_opt & DO_TRANS_BUILDINGS) {
+			if (HASBIT(_transparent_opt, TO_BUILDINGS)) {
 				SETBIT(image, PALETTE_MODIFIER_TRANSPARENT);
 				pal = PALETTE_TO_TRANSPARENT;
 			} else if (HASBIT(image, PALETTE_MODIFIER_COLOR)) {