diff --git a/libc/include/mntent.h b/libc/include/mntent.h
index b5fb98c..ad9d72f 100644
--- a/libc/include/mntent.h
+++ b/libc/include/mntent.h
@@ -61,7 +61,7 @@
 struct mntent* getmntent(FILE*);
 struct mntent* getmntent_r(FILE*, struct mntent*, char*, int) __INTRODUCED_IN(21);
 FILE* setmntent(const char*, const char*) __INTRODUCED_IN(21);
-char* hasmntopt(const struct mntent*, const char*) __INTRODUCED_IN(25);
+char* hasmntopt(const struct mntent*, const char*) __INTRODUCED_IN_FUTURE;
 
 __END_DECLS