@@ -1317,7 +1317,7 @@ static int GrowTownAtRoad(Town *t, TileI
/* Exclude the source position from the bitmask
* and return if no more road blocks available */
cur_rb &= ~DiagDirToRoadBits(ReverseDiagDir(target_dir));
if (IsValidDiagDirection(target_dir)) cur_rb &= ~DiagDirToRoadBits(ReverseDiagDir(target_dir));
if (cur_rb == ROAD_NONE) {
return _grow_town_result;
}