diff --git a/newgrf.c b/newgrf.c
index 6d0735bb3e..9b54e95eff 100644
--- a/newgrf.c
+++ b/newgrf.c
@@ -43,7 +43,7 @@ SpriteID _signal_base = 0;
 static GRFFile *_cur_grffile;
 GRFFile *_first_grffile;
 GRFConfig *_first_grfconfig;
-static int _cur_spriteid;
+static SpriteID _cur_spriteid;
 static int _cur_stage;
 static uint32 _nfo_line;
 
diff --git a/newgrf.h b/newgrf.h
index 5bf2359fc8..ec1830307a 100644
--- a/newgrf.h
+++ b/newgrf.h
@@ -33,7 +33,7 @@ typedef struct GRFFile {
 	 * half-filled wagon etc.  Each spriteset contains eight sprites (one
 	 * per direction) or four sprites if the vehicle is symmetric. */
 
-	int spriteset_start;
+	SpriteID spriteset_start;
 	int spriteset_numsets;
 	int spriteset_numents;
 	int spriteset_feature;