diff --git a/src/newgrf_house.cpp b/src/newgrf_house.cpp
--- a/src/newgrf_house.cpp
+++ b/src/newgrf_house.cpp
@@ -610,7 +610,7 @@ static void DoTriggerHouse(TileIndex til
 	HouseID hid = GetHouseType(tile);
 	HouseSpec *hs = HouseSpec::Get(hid);
 
-	if (hs->grf_prop.spritegroup == NULL) return;
+	if (hs->grf_prop.spritegroup[0] == NULL) return;
 
 	HouseResolverObject object(hid, tile, Town::GetByTile(tile), CBID_RANDOM_TRIGGER);
 	object.trigger = trigger;