--- Libc/Libc-1244.20.1/include/stdlib.h
+++ Libc/Libc-1244.50.9/include/stdlib.h
@@ -237,6 +237,11 @@
 long	 nrand48(unsigned short[3]) __swift_unavailable("Use arc4random instead.");
 int	 posix_openpt(int);
 char	*ptsname(int);
+
+#if (!defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE))
+int ptsname_r(int fildes, char *buffer, size_t buflen) __API_AVAILABLE(macos(10.13.4), ios(11.3), tvos(11.3), watchos(4.3));
+#endif
+
 //Begin-Libc
 #ifndef LIBC_ALIAS_PUTENV
 //End-Libc