Index: include/stdlib.h
===================================================================
--- include/stdlib.h
+++ include/stdlib.h
@@ -225,7 +225,6 @@
 long	 nrand48(unsigned short[3]);
 int	 posix_openpt(int);
 char	*ptsname(int);
-int	 ptsname_r(int, char *, size_t);
 int	 putenv(char *);
 long	 random(void);
 unsigned short
@@ -237,6 +236,7 @@
 #endif /* __XSI_VISIBLE */
 
 #if __BSD_VISIBLE
+int	 ptsname_r(int, char *, size_t);
 extern const char *malloc_conf;
 extern void (*malloc_message)(void *, const char *);
 
Index: lib/libc/stdlib/Symbol.map
===================================================================
--- lib/libc/stdlib/Symbol.map
+++ lib/libc/stdlib/Symbol.map
@@ -122,10 +122,10 @@
 };
 
 FBSD_1.6 {
+	ptsname_r;
 	qsort_s;
 	rand;
 	srand;
-	ptsname_r;
 };
 
 FBSDprivate_1.0 {
Index: lib/libc/stdlib/ptsname.c
===================================================================
--- lib/libc/stdlib/ptsname.c
+++ lib/libc/stdlib/ptsname.c
@@ -71,12 +71,8 @@
 __strong_reference(__isptmaster, grantpt);
 __strong_reference(__isptmaster, unlockpt);
 
-/*
- * ptsname_r(): return the pathname of the slave pseudo-terminal device
- *              associated with the specified master.
- */
-int
-ptsname_r(int fildes, char *buffer, size_t buflen)
+static int
+__ptsname_r(int fildes, char *buffer, size_t buflen)
 {
 
 	if (buflen <= sizeof(_PATH_DEV)) {
@@ -101,6 +97,18 @@
 	return (0);
 }
 
+/*
+ * ptsname_r(): return the pathname of the slave pseudo-terminal device
+ *              associated with the specified master.
+ */
+#pragma weak ptsname_r
+int
+ptsname_r(int fildes, char *buffer, size_t buflen)
+{
+
+	return (__ptsname_r(fildes, buffer, buflen));
+}
+
 /*
  * ptsname():  return the pathname of the slave pseudo-terminal device
  *             associated with the specified master.
@@ -108,10 +116,10 @@
 char *
 ptsname(int fildes)
 {
-	static char pt_slave[sizeof _PATH_DEV + SPECNAMELEN];
+	static char pt_slave[sizeof(_PATH_DEV) + SPECNAMELEN];
 
-	if (ptsname_r(fildes, pt_slave, sizeof(pt_slave)) == 0)
+	if (__ptsname_r(fildes, pt_slave, sizeof(pt_slave)) == 0)
 		return (pt_slave);
-	else
-		return (NULL);
+
+	return (NULL);
 }