diff --git a/libc/include/stdlib.h b/libc/include/stdlib.h
index acfe694..41e8d26 100644
--- a/libc/include/stdlib.h
+++ b/libc/include/stdlib.h
@@ -132,7 +132,7 @@
 
 extern int    unlockpt(int);
 extern char*  ptsname(int);
-extern char*  ptsname_r(int, char*, size_t);
+extern int    ptsname_r(int, char*, size_t);
 extern int    getpt(void);
 
 static __inline__ int grantpt(int __fd)