1 files changed, 1 insertions, 0 deletions
diff --git a/src/gfx_type.h b/src/gfx_type.h
index 558519fb0..20b5019a0 100644
--- a/src/gfx_type.h
+++ b/src/gfx_type.h
@@ -240,6 +240,7 @@ enum SpriteType {
 	ST_MAPGEN   = 1,      ///< Special sprite for the map generator
 	ST_FONT     = 2,      ///< A sprite used for fonts
 	ST_RECOLOUR = 3,      ///< Recolour sprite
+	ST_INVALID  = 4,      ///< Pseudosprite or other unusable sprite, used only internally
 };
 
 #endif /* GFX_TYPE_H */