diff --git a/mkdio.h.in b/mkdio.h.in
index 62492e4..0cc44b8 100644
--- a/mkdio.h.in
+++ b/mkdio.h.in
@@ -48,6 +48,7 @@ typedef void mkd_flag_t;
 int mkd_flag_isset(mkd_flag_t*, int);		/* check a flag status */
 
 mkd_flag_t *mkd_flags();			/* create a flag blob */
+mkd_flag_t *mkd_copy_flags(mkd_flag_t*);	/* copy a flag blob */
 void mkd_free_flags(mkd_flag_t*);		/* delete a flag blob */
 char *mkd_set_flag_string(mkd_flag_t*, char*);	/* set named flags */
 void mkd_set_flag_num(mkd_flag_t*, unsigned long);/* set a specific flag */