diff --git a/src/engine.cpp b/src/engine.cpp
--- a/src/engine.cpp
+++ b/src/engine.cpp
@@ -722,11 +722,9 @@ static void EnableEngineForCompany(Engin
 
 	SetBit(e->company_avail, company);
 	if (e->type == VEH_TRAIN) {
-		assert(e->u.rail.railtype < RAILTYPE_END);
-		c->avail_railtypes = AddDateIntroducedRailTypes(c->avail_railtypes | GetRailTypeInfo(e->u.rail.railtype)->introduces_railtypes, _date);
+		c->avail_railtypes = GetCompanyRailtypes(c->index);
 	} else if (e->type == VEH_ROAD) {
-		assert(e->u.road.roadtype < ROADTYPE_END);
-		c->avail_roadtypes = AddDateIntroducedRoadTypes(c->avail_roadtypes | GetRoadTypeInfo(e->u.road.roadtype)->introduces_roadtypes, _date);
+		c->avail_roadtypes = GetCompanyRoadTypes(c->index);
 	}
 
 	if (company == _local_company) {