diff --git a/road_cmd.c b/road_cmd.c
--- a/road_cmd.c
+++ b/road_cmd.c
@@ -428,7 +428,7 @@ int32 CmdBuildRoad(int x, int y, uint32 
 				goto do_clear;
 
 		/* only allow roads pertendicular to bridge */
-		if ((pieces & 5U) == (ti.map5 & 0x01U))
+		if (((pieces & 5U) != 0) == ((ti.map5 & 0x01U) != 0))
 				goto do_clear;
 
 		/* check if clear land under bridge */