diff --git a/include/stdlib.h b/include/stdlib.h
index 5c8e4e363ef0..cd157064a058 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -164,6 +164,18 @@ int	 setenv(const char *, const char *, int);
 int	 unsetenv(const char *);
 #endif
 
+#if __POSIX_VISIBLE >= 200809 || __XSI_VISIBLE
+int	 getsubopt(char **, char *const *, char **);
+#ifndef _MKDTEMP_DECLARED
+char	*mkdtemp(char *);
+#define	_MKDTEMP_DECLARED
+#endif
+#ifndef _MKSTEMP_DECLARED
+int	 mkstemp(char *);
+#define	_MKSTEMP_DECLARED
+#endif
+#endif /* __POSIX_VISIBLE >= 200809 || __XSI_VISIBLE */
+
 /*
  * The only changes to the XSI namespace in revision 6 were the deletion
  * of the ttyslot() and valloc() functions, which FreeBSD never declared
@@ -178,18 +190,13 @@ double	 drand48(void);
 double	 erand48(unsigned short[3]);
 /* char	*fcvt(double, int, int * __restrict, int * __restrict); */
 /* char	*gcvt(double, int, int * __restrict, int * __restrict); */
-int	 getsubopt(char **, char *const *, char **);
 int	 grantpt(int);
 char	*initstate(unsigned long /* XSI requires u_int */, char *, long);
 long	 jrand48(unsigned short[3]);
 char	*l64a(long);
 void	 lcong48(unsigned short[7]);
 long	 lrand48(void);
-#ifndef _MKSTEMP_DECLARED
-int	 mkstemp(char *);
-#define	_MKSTEMP_DECLARED
-#endif
-#ifndef _MKTEMP_DECLARED
+#if !defined(_MKTEMP_DECLARED) && __XSI_VISIBLE <= 600
 char	*mktemp(char *);
 #define	_MKTEMP_DECLARED
 #endif