diff --git a/src/ai/default/default.cpp b/src/ai/default/default.cpp
index f015de8be5..957993edb8 100644
--- a/src/ai/default/default.cpp
+++ b/src/ai/default/default.cpp
@@ -3269,7 +3269,7 @@ static void AiStateAirportStuff(Player *p)
 
 			AirportFTAClass::Flags flags = GetAirport(st->airport_type)->flags;
 
-			if (!(flags & (p->ai.build_kind == 1 && i == 0 ? AirportFTAClass::HELICOPTERS : AirportFTAClass::PLANES))) {
+			if (!(flags & (p->ai.build_kind == 1 && i == 0 ? AirportFTAClass::HELICOPTERS : AirportFTAClass::AIRPLANES))) {
 				continue;
 			}
 
@@ -3292,7 +3292,7 @@ static void AiStateAirportStuff(Player *p)
 			 * broken because they will probably need different
 			 * tileoff values etc), no matter that
 			 * IsHangarTile() makes no sense. --pasky */
-			if (!(flags & AirportFTAClass::PLANES)) {
+			if (!(flags & AirportFTAClass::AIRPLANES)) {
 				/* Heliports should have maybe own rulesets but
 				 * OTOH we don't want AI to pick them up when
 				 * looking for a suitable airport type to build.
diff --git a/src/aircraft_cmd.cpp b/src/aircraft_cmd.cpp
index 7c25d417d0..4e74c335e1 100644
--- a/src/aircraft_cmd.cpp
+++ b/src/aircraft_cmd.cpp
@@ -251,7 +251,7 @@ int32 CmdBuildAircraft(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 	// Prevent building aircraft types at places which can't handle them
 	const Station* st = GetStationByTile(tile);
 	const AirportFTAClass* apc = GetAirport(st->airport_type);
-	if (!(apc->flags & (avi->subtype & AIR_CTOL ? AirportFTAClass::PLANES : AirportFTAClass::HELICOPTERS))) {
+	if (!(apc->flags & (avi->subtype & AIR_CTOL ? AirportFTAClass::AIRPLANES : AirportFTAClass::HELICOPTERS))) {
 		return CMD_ERROR;
 	}
 
@@ -1640,7 +1640,7 @@ static void AircraftEventHandler_Flying(Vehicle *v, const AirportFTAClass *apc)
 
 	st = GetStation(v->u.air.targetairport);
 	// runway busy or not allowed to use this airstation, circle
-	if (apc->flags & (v->subtype == AIR_HELICOPTER ? AirportFTAClass::HELICOPTERS : AirportFTAClass::PLANES) &&
+	if (apc->flags & (v->subtype == AIR_HELICOPTER ? AirportFTAClass::HELICOPTERS : AirportFTAClass::AIRPLANES) &&
 			st->airport_tile != 0 &&
 			(st->owner == OWNER_NONE || st->owner == v->owner)) {
 		// {32,FLYING,NOTHING_block,37}, {32,LANDING,N,33}, {32,HELILANDING,N,41},
diff --git a/src/airport.h b/src/airport.h
index dd5ebabce1..83cb4eda3f 100644
--- a/src/airport.h
+++ b/src/airport.h
@@ -122,9 +122,9 @@ struct AirportFTAbuildup;
 typedef struct AirportFTAClass {
 	public:
 		enum Flags {
-			PLANES      = 0x1,
+			AIRPLANES   = 0x1,
 			HELICOPTERS = 0x2,
-			ALL         = PLANES | HELICOPTERS,
+			ALL         = AIRPLANES | HELICOPTERS,
 			SHORT_STRIP = 0x4
 		};