diff --git a/libc/include/stdlib.h b/libc/include/stdlib.h
index 41e8d26..5a991ac 100644
--- a/libc/include/stdlib.h
+++ b/libc/include/stdlib.h
@@ -135,7 +135,7 @@
 extern int    ptsname_r(int, char*, size_t);
 extern int    getpt(void);
 
-static __inline__ int grantpt(int __fd)
+static __inline__ int grantpt(int __fd __attribute((unused)))
 {
   (void)__fd;
   return 0;     /* devpts does this all for us! */