Use zip_XXX_t instead of struct zip_XXX or enum zip_XXX.
diff --git a/lib/zip_add_dir.c b/lib/zip_add_dir.c
index 65abceb..14bdeda 100644
--- a/lib/zip_add_dir.c
+++ b/lib/zip_add_dir.c
@@ -39,7 +39,7 @@
 /* NOTE: Signed due to -1 on error.  See zip_add.c for more details. */
 
 ZIP_EXTERN zip_int64_t
-zip_add_dir(struct zip *za, const char *name)
+zip_add_dir(zip_t *za, const char *name)
 {
     return zip_dir_add(za, name, 0);
 }