diff --git a/src/newgrf_spritegroup.h b/src/newgrf_spritegroup.h
--- a/src/newgrf_spritegroup.h
+++ b/src/newgrf_spritegroup.h
@@ -373,12 +373,6 @@ struct ResolverObject {
 			uint8 count;
 			uint8 station_size;
 		} generic;
-		struct {
-			struct Station *st;            ///< Station of the airport for which the callback is run, or NULL for build gui.
-			byte airport_id;               ///< Type of airport for which the callback is run
-			byte layout;                   ///< Layout of the airport to build.
-			TileIndex tile;                ///< Tile for the callback, only valid for airporttile callbacks.
-		} airport;
 	} u;
 
 	uint32 (*GetRandomBits)(const struct ResolverObject*);