diff --git a/ai/default/default.c b/ai/default/default.c
index 7b89d0b1f0..cb17433e6c 100644
--- a/ai/default/default.c
+++ b/ai/default/default.c
@@ -156,7 +156,7 @@ static EngineID AiChooseTrainToBuild(byte railtype, int32 money, byte flag, Tile
 	return best_veh_index;
 }
 
-static EngineID AiChooseRoadVehToBuild(byte cargo, int32 money, TileIndex tile)
+static EngineID AiChooseRoadVehToBuild(CargoID cargo, int32 money, TileIndex tile)
 {
 	EngineID best_veh_index = INVALID_ENGINE;
 	int32 best_veh_cost = 0;
@@ -431,7 +431,7 @@ static void AiStateDoReplaceVehicle(Player *p)
 
 typedef struct FoundRoute {
 	int distance;
-	byte cargo;
+	CargoID cargo;
 	void *from;
 	void *to;
 } FoundRoute;
@@ -451,7 +451,7 @@ static Industry *AiFindRandomIndustry(void)
 static void AiFindSubsidyIndustryRoute(FoundRoute *fr)
 {
 	uint i;
-	byte cargo;
+	CargoID cargo;
 	Subsidy *s;
 	Industry *from, *to_ind;
 	Town *to_tow;
@@ -468,7 +468,7 @@ static void AiFindSubsidyIndustryRoute(FoundRoute *fr)
 
 	// Don't want passengers or mail
 	cargo = s->cargo_type;
-	if (cargo == 0xFF || cargo == CT_PASSENGERS || cargo == CT_MAIL || s->age > 7)
+	if (cargo == CT_INVALID || cargo == CT_PASSENGERS || cargo == CT_MAIL || s->age > 7)
 		return;
 	fr->cargo = cargo;
 
@@ -522,7 +522,7 @@ static void AiFindRandomIndustryRoute(FoundRoute *fr)
 	Industry *i,*i2;
 	Town *t;
 	uint32 r;
-	byte cargo;
+	CargoID cargo;
 
 	// initially error
 	fr->distance = -1;
@@ -535,7 +535,7 @@ static void AiFindRandomIndustryRoute(FoundRoute *fr)
 
 	// pick a random produced cargo
 	cargo = i->produced_cargo[0];
-	if (r & 1 && i->produced_cargo[1] != 0xFF) cargo = i->produced_cargo[1];
+	if (r & 1 && i->produced_cargo[1] != CT_INVALID) cargo = i->produced_cargo[1];
 
 	fr->cargo = cargo;
 
diff --git a/ai/trolly/trolly.c b/ai/trolly/trolly.c
index 9f00579cb7..006e04850e 100644
--- a/ai/trolly/trolly.c
+++ b/ai/trolly/trolly.c
@@ -286,7 +286,7 @@ static bool AiNew_Check_City_or_Industry(Player *p, int ic, byte type)
 
 		// No limits on delevering stations!
 		//  Or for industry that does not give anything yet
-		if (i->produced_cargo[0] == 0xFF || i->total_production[0] == 0) return true;
+		if (i->produced_cargo[0] == CT_INVALID || i->total_production[0] == 0) return true;
 
 		if (i->total_production[0] - i->total_transported[0] < AI_CHECKCITY_NEEDED_CARGO) return false;
 
@@ -312,7 +312,7 @@ static bool AiNew_Check_City_or_Industry(Player *p, int ic, byte type)
 				//  we want to know if this station gets the same good. If so,
 				//  we want to know its rating. If it is too high, we are not going
 				//  to build there
-				if (i->produced_cargo[0] == 0xFF) continue;
+				if (i->produced_cargo[0] == CT_INVALID) continue;
 				// It does not take this cargo
 				if (!st->goods[i->produced_cargo[0]].last_speed) continue;
 				// Is it around our industry
@@ -464,9 +464,9 @@ static void AiNew_State_LocateRoute(Player *p)
 			int i;
 			// TODO: in max_cargo, also check other cargo (beside [0])
 			// First we check if the from_ic produces cargo that this ic accepts
-			if (GetIndustry(p->ainew.from_ic)->produced_cargo[0] != 0xFF && GetIndustry(p->ainew.from_ic)->total_production[0] != 0) {
+			if (GetIndustry(p->ainew.from_ic)->produced_cargo[0] != CT_INVALID && GetIndustry(p->ainew.from_ic)->total_production[0] != 0) {
 				for (i=0;i<3;i++) {
-					if (GetIndustry(p->ainew.temp)->accepts_cargo[i] == 0xFF) break;
+					if (GetIndustry(p->ainew.temp)->accepts_cargo[i] == CT_INVALID) break;
 					if (GetIndustry(p->ainew.from_ic)->produced_cargo[0] == GetIndustry(p->ainew.temp)->accepts_cargo[i]) {
 						// Found a compatbiel industry
 						max_cargo = GetIndustry(p->ainew.from_ic)->total_production[0] - GetIndustry(p->ainew.from_ic)->total_transported[0];
@@ -477,10 +477,10 @@ static void AiNew_State_LocateRoute(Player *p)
 					}
 				}
 			}
-			if (!found && GetIndustry(p->ainew.temp)->produced_cargo[0] != 0xFF && GetIndustry(p->ainew.temp)->total_production[0] != 0) {
+			if (!found && GetIndustry(p->ainew.temp)->produced_cargo[0] != CT_INVALID && GetIndustry(p->ainew.temp)->total_production[0] != 0) {
 				// If not check if the current ic produces cargo that the from_ic accepts
 				for (i=0;i<3;i++) {
-					if (GetIndustry(p->ainew.from_ic)->accepts_cargo[i] == 0xFF) break;
+					if (GetIndustry(p->ainew.from_ic)->accepts_cargo[i] == CT_INVALID) break;
 					if (GetIndustry(p->ainew.temp)->produced_cargo[0] == GetIndustry(p->ainew.from_ic)->accepts_cargo[i]) {
 						// Found a compatbiel industry
 						found = true;
diff --git a/economy.c b/economy.c
index f957eb6874..86aebd70e7 100644
--- a/economy.c
+++ b/economy.c
@@ -908,7 +908,7 @@ void DeleteSubsidyWithStation(uint16 index)
 
 typedef struct FoundRoute {
 	uint distance;
-	byte cargo;
+	CargoID cargo;
 	void *from;
 	void *to;
 } FoundRoute;
@@ -934,7 +934,7 @@ static void FindSubsidyCargoRoute(FoundRoute *fr)
 {
 	Industry *i;
 	int trans, total;
-	byte cargo;
+	CargoID cargo;
 
 	fr->distance = (uint)-1;
 
@@ -1102,9 +1102,9 @@ static void Load_SUBS(void)
 		SlObject(&_subsidies[index], _subsidies_desc);
 }
 
-int32 GetTransportedGoodsIncome(uint num_pieces, uint dist, byte transit_days, byte cargo_type)
+int32 GetTransportedGoodsIncome(uint num_pieces, uint dist, byte transit_days, CargoID cargo_type)
 {
-	int cargo = cargo_type;
+	CargoID cargo = cargo_type;
 	byte f;
 
 	/* zero the distance if it's the bank and very short transport. */
@@ -1131,7 +1131,7 @@ int32 GetTransportedGoodsIncome(uint num_pieces, uint dist, byte transit_days, b
 	return BIGMULSS(dist * f * num_pieces, _cargo_payment_rates[cargo], 21);
 }
 
-static void DeliverGoodsToIndustry(TileIndex xy, byte cargo_type, int num_pieces)
+static void DeliverGoodsToIndustry(TileIndex xy, CargoID cargo_type, int num_pieces)
 {
 	Industry* best = NULL;
 	Industry* ind;
@@ -1162,7 +1162,7 @@ static void DeliverGoodsToIndustry(TileIndex xy, byte cargo_type, int num_pieces
 	}
 }
 
-static bool CheckSubsidised(Station *from, Station *to, byte cargo_type)
+static bool CheckSubsidised(Station *from, Station *to, CargoID cargo_type)
 {
 	Subsidy *s;
 	TileIndex xy;
@@ -1230,7 +1230,7 @@ static bool CheckSubsidised(Station *from, Station *to, byte cargo_type)
 	return false;
 }
 
-static int32 DeliverGoods(int num_pieces, byte cargo_type, uint16 source, uint16 dest, byte days_in_transit)
+static int32 DeliverGoods(int num_pieces, CargoID cargo_type, uint16 source, uint16 dest, byte days_in_transit)
 {
 	bool subsidised;
 	Station *s_from, *s_to;
diff --git a/economy.h b/economy.h
index 00c7ce4ddc..72d259697f 100644
--- a/economy.h
+++ b/economy.h
@@ -21,7 +21,7 @@ typedef struct {
 VARDEF Economy _economy;
 
 typedef struct Subsidy {
-	byte cargo_type;
+	CargoID cargo_type;
 	byte age;
 	uint16 from;
 	uint16 to;
@@ -64,7 +64,7 @@ Pair SetupSubsidyDecodeParam(const Subsidy* s, bool mode);
 void DeleteSubsidyWithIndustry(uint16 index);
 void DeleteSubsidyWithStation(uint16 index);
 
-int32 GetTransportedGoodsIncome(uint num_pieces, uint dist, byte transit_days, byte cargo_type);
+int32 GetTransportedGoodsIncome(uint num_pieces, uint dist, byte transit_days, CargoID cargo_type);
 uint MoveGoodsToStation(TileIndex tile, int w, int h, int type, uint amount);
 
 #endif /* ECONOMY_H */
diff --git a/engine.h b/engine.h
index 14e21f311a..f35f9570c4 100644
--- a/engine.h
+++ b/engine.h
@@ -20,7 +20,7 @@ typedef struct RailVehicleInfo {
 	byte running_cost_class;
 	byte engclass; // 0: steam, 1: diesel, 2: electric
 	byte capacity;
-	byte cargo_type;
+	CargoID cargo_type;
 	byte ai_rank;
 	byte callbackmask; // see CallbackMask enum
 	uint16 pow_wag_power;
@@ -36,7 +36,7 @@ typedef struct ShipVehicleInfo {
 	byte image_index;
 	byte base_cost;
 	uint16 max_speed;
-	byte cargo_type;
+	CargoID cargo_type;
 	uint16 capacity;
 	byte running_cost;
 	byte sfx;
@@ -64,7 +64,7 @@ typedef struct RoadVehicleInfo {
 	byte sfx;
 	byte max_speed;
 	byte capacity;
-	byte cargo_type;
+	CargoID cargo_type;
 	byte callbackmask;
 } RoadVehicleInfo;
 
diff --git a/graph_gui.c b/graph_gui.c
index 157726c9e4..ea7a40aa6b 100644
--- a/graph_gui.c
+++ b/graph_gui.c
@@ -693,7 +693,8 @@ static void CargoPaymentRatesWndProc(Window *w, WindowEvent *e)
 {
 	switch (e->event) {
 	case WE_PAINT: {
-		int i, j, x, y;
+		int j, x, y;
+		CargoID i;
 		GraphDrawer gd;
 
 		gd.sel = _legend_cargobits;
diff --git a/industry.h b/industry.h
index ef2ec6f386..d2e67304c7 100644
--- a/industry.h
+++ b/industry.h
@@ -10,10 +10,10 @@ struct Industry {
 	byte width; /* swapped order of w/h with town */
 	byte height;
 	const Town* town;
-	byte produced_cargo[2];
+	CargoID produced_cargo[2];
 	uint16 cargo_waiting[2];
 	byte production_rate[2];
-	byte accepts_cargo[3];
+	CargoID accepts_cargo[3];
 	byte prod_level;
 	uint16 last_mo_production[2];
 	uint16 last_mo_transported[2];
diff --git a/industry_cmd.c b/industry_cmd.c
index 4fe8afe51d..d7f3170f9e 100644
--- a/industry_cmd.c
+++ b/industry_cmd.c
@@ -82,9 +82,9 @@ typedef struct IndustrySpec {
 	const IndustryTileTable *const *table;
 	byte num_table;
 	byte a,b,c;
-	byte produced_cargo[2];
+	CargoID produced_cargo[2];
 	byte production_rate[2];
-	byte accepts_cargo[3];
+	CargoID accepts_cargo[3];
 	byte check_proc;
 } IndustrySpec;
 
@@ -858,7 +858,7 @@ static uint32 GetTileTrackStatus_Industry(TileIndex tile, TransportType mode)
 	return 0;
 }
 
-static void GetProducedCargo_Industry(TileIndex tile, byte *b)
+static void GetProducedCargo_Industry(TileIndex tile, CargoID *b)
 {
 	const Industry* i = GetIndustryByTile(tile);
 
diff --git a/newgrf_engine.c b/newgrf_engine.c
index 1c408200fd..5fd6c0189a 100644
--- a/newgrf_engine.c
+++ b/newgrf_engine.c
@@ -375,7 +375,7 @@ static const SpriteGroup* ResolveVehicleSpriteGroup(const SpriteGroup *spritegro
 static const SpriteGroup *GetVehicleSpriteGroup(EngineID engine, const Vehicle *v)
 {
 	const SpriteGroup *group;
-	byte cargo = GC_PURCHASE;
+	CargoID cargo = GC_PURCHASE;
 
 	if (v != NULL) {
 		cargo = _global_cargo_id[_opt.landscape][v->cargo_type];
diff --git a/openttd.h b/openttd.h
index 6c41ee5478..b32d5c5400 100644
--- a/openttd.h
+++ b/openttd.h
@@ -320,7 +320,7 @@ typedef void GetTileDescProc(TileIndex tile, TileDesc *td);
  * above.
  */
 typedef uint32 GetTileTrackStatusProc(TileIndex tile, TransportType mode);
-typedef void GetProducedCargoProc(TileIndex tile, byte *b);
+typedef void GetProducedCargoProc(TileIndex tile, CargoID *b);
 typedef void ClickTileProc(TileIndex tile);
 typedef void AnimateTileProc(TileIndex tile);
 typedef void TileLoopProc(TileIndex tile);
diff --git a/player.h b/player.h
index 32fab10a62..e6ed1fe2e7 100644
--- a/player.h
+++ b/player.h
@@ -26,7 +26,7 @@ typedef struct AiBuildRec {
 	byte buildcmd_a;
 	byte buildcmd_b;
 	byte direction;
-	byte cargo;
+	CargoID cargo;
 } AiBuildRec;
 
 typedef struct PlayerAI {
@@ -39,7 +39,7 @@ typedef struct PlayerAI {
 	byte banned_tile_count;
 	byte railtype_to_use;
 
-	byte cargo_type;
+	CargoID cargo_type;
 	byte num_wagons;
 	byte build_kind;
 	byte num_build_rec;
@@ -111,7 +111,7 @@ typedef struct PlayerAiNew {
 
 	// Route stuff
 
-	byte cargo;
+	CargoID cargo;
 	byte tbt; // train/bus/truck 0/1/2 AI_TRAIN/AI_BUS/AI_TRUCK
 	int new_cost;
 
diff --git a/station_cmd.c b/station_cmd.c
index f6ee2d2b06..986e732411 100644
--- a/station_cmd.c
+++ b/station_cmd.c
@@ -554,7 +554,7 @@ void GetProductionAroundTiles(AcceptedCargo produced, TileIndex tile,
 
 				gpc = _tile_type_procs[GetTileType(tile)]->get_produced_cargo_proc;
 				if (gpc != NULL) {
-					byte cargos[2] = { CT_INVALID, CT_INVALID };
+					CargoID cargos[2] = { CT_INVALID, CT_INVALID };
 
 					gpc(tile, cargos);
 					if (cargos[0] != CT_INVALID) {
diff --git a/vehicle.h b/vehicle.h
index f2ce6efb1c..63f6bbdf13 100644
--- a/vehicle.h
+++ b/vehicle.h
@@ -178,7 +178,7 @@ struct Vehicle {
 	byte vehstatus;		// Status
 	uint16 last_station_visited;
 
-	byte cargo_type;	// type of cargo this vehicle is carrying
+	CargoID cargo_type;	// type of cargo this vehicle is carrying
 	byte cargo_days; // how many days have the pieces been in transit
 	uint16 cargo_source;// source of cargo
 	uint16 cargo_cap;	// total capacity
diff --git a/window.h b/window.h
index 54df4c76e2..11e4049bb6 100644
--- a/window.h
+++ b/window.h
@@ -387,7 +387,7 @@ assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(facesel_d));
 
 typedef struct {
 	int sel;
-	byte cargo;
+	CargoID cargo;
 } refit_d;
 assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(refit_d));