diff --git a/src/newgrf_airporttiles.h b/src/newgrf_airporttiles.h
--- a/src/newgrf_airporttiles.h
+++ b/src/newgrf_airporttiles.h
@@ -33,7 +33,7 @@ struct AirportTileSpec {
 	uint8 animation_speed;                ///< The speed of the animation
 
 	StringID name;                        ///< Tile Subname string, land information on this tile will give you "AirportName (TileSubname)"
-	uint8 callback_flags;                 ///< Flags telling which grf callback is set
+	uint8 callback_mask;                  ///< Bitmask telling which grf callback is set
 	uint8 animation_triggers;             ///< When to start the animation
 	uint8 animation_special_flags;        ///< Extra flags to influence the animation
 	bool enabled;                         ///< entity still available (by default true). newgrf can disable it, though