diff --git a/libc/include/mntent.h b/libc/include/mntent.h
index 43cab1f..9a31838 100644
--- a/libc/include/mntent.h
+++ b/libc/include/mntent.h
@@ -57,10 +57,10 @@
 
 __BEGIN_DECLS
 
-int endmntent(FILE* _Nullable __fp) __INTRODUCED_IN(21);
+int endmntent(FILE* _Nullable __fp);
 struct mntent* _Nullable getmntent(FILE* _Nonnull __fp);
-struct mntent* _Nullable getmntent_r(FILE* _Nonnull __fp, struct mntent* _Nonnull __entry, char* _Nonnull __buf, int __size) __INTRODUCED_IN(21);
-FILE* _Nullable setmntent(const char* _Nonnull __filename, const char* _Nonnull __type) __INTRODUCED_IN(21);
+struct mntent* _Nullable getmntent_r(FILE* _Nonnull __fp, struct mntent* _Nonnull __entry, char* _Nonnull __buf, int __size);
+FILE* _Nullable setmntent(const char* _Nonnull __filename, const char* _Nonnull __type);
 char* _Nullable hasmntopt(const struct mntent* _Nonnull __entry, const char* _Nonnull __option) __INTRODUCED_IN(26);
 
 __END_DECLS