diff --git a/libc/include/time.h b/libc/include/time.h
index 039608b..ef4ac2f 100644
--- a/libc/include/time.h
+++ b/libc/include/time.h
@@ -100,8 +100,8 @@
 extern int timer_getoverrun(timer_t) __LIBC_ABI_PUBLIC__;
 
 /* Non-standard extensions that are in the BSDs and glibc. */
-extern time_t timelocal(struct tm*) __LIBC_ABI_PUBLIC__ __INTRODUCED_IN(21);
-extern time_t timegm(struct tm*) __LIBC_ABI_PUBLIC__ __INTRODUCED_IN(21);
+extern time_t timelocal(struct tm*) __LIBC_ABI_PUBLIC__ __INTRODUCED_IN(12);
+extern time_t timegm(struct tm*) __LIBC_ABI_PUBLIC__ __INTRODUCED_IN(12);
 
 __END_DECLS