-extern int x_create_bitmap_from_data (struct frame *, char *,
- unsigned int, unsigned int);
-extern int x_create_bitmap_from_file (struct frame *, Lisp_Object);
+extern ptrdiff_t x_create_bitmap_from_data (struct frame *, char *,
+ unsigned int, unsigned int);
+extern ptrdiff_t x_create_bitmap_from_file (struct frame *, Lisp_Object);