diff --git a/include/unistd.h b/include/unistd.h
index 9227c63d0a06..977e9b109d72 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -489,7 +489,12 @@ int	 rresvport(int *);
 int	 rresvport_af(int *, int);
 int	 ruserok(const char *, int, const char *, const char *);
 void	*sbrk(intptr_t);
+#if __BSD_VISIBLE
+#ifndef _SELECT_DECLARED
+#define	_SELECT_DECLARED
 int	 select(int, fd_set *, fd_set *, fd_set *, struct timeval *);
+#endif
+#endif
 int	 setdomainname(const char *, int);
 int	 setgroups(int, const gid_t *);
 void	 sethostid(long);
diff --git a/sys/sys/select.h b/sys/sys/select.h
index 396edae81dc6..11aacdd1e513 100644
--- a/sys/sys/select.h
+++ b/sys/sys/select.h
@@ -43,23 +43,61 @@
 #include <sys/timespec.h>
 
 /*
+ * XXX
  * Other things required for this header which we do not presently implement:
  *
  * struct timeval (with suseconds_t)
- * fd_set
- * FD_* macros
- *
- * Temporarily get all of these things from <sys/types.h>, which has too
- * much pollution to be used here but will do for now.  (Eventually, the
- * latter two will move to this file and be included *from* <sys/types.h>
- * in the BSD namespace.)
  */
-#include <sys/types.h>	/* XXX dependency reversed */
+
+typedef	unsigned long	__fd_mask;
+#if __BSD_VISIBLE
+typedef	__fd_mask	fd_mask;
+#endif
+
+/*
+ * Select uses bit masks of file descriptors in longs.  These macros
+ * manipulate such bit fields (the filesystem macros use chars).
+ * FD_SETSIZE may be defined by the user, but the default here should
+ * be enough for most uses.
+ */
+#ifndef	FD_SETSIZE
+#define	FD_SETSIZE	1024U
+#endif
+
+#define	_NFDBITS	(sizeof(__fd_mask) * 8)	/* bits per mask */
+#if __BSD_VISIBLE
+#define	NFDBITS		_NFDBITS
+#endif
+
+#ifndef _howmany
+#define	_howmany(x, y)	(((x) + ((y) - 1)) / (y))
+#endif
+
+typedef	struct fd_set {
+	__fd_mask	fds_bits[_howmany(FD_SETSIZE, _NFDBITS)];
+} fd_set;
+
+#define	__fdset_mask(n)	((fd_mask)1 << ((n) % _NFDBITS))
+#define	FD_CLR(n, p)	((p)->fds_bits[(n)/_NFDBITS] &= ~__fdset_mask(n))
+#if __BSD_VISIBLE
+/* XXX bcopy() not in scope, so <strings.h> is required; see also FD_ZERO(). */
+#define	FD_COPY(f, t)	bcopy(f, t, sizeof(*(f)))
+#endif
+#define	FD_ISSET(n, p)	((p)->fds_bits[(n)/_NFDBITS] & __fdset_mask(n))
+#define	FD_SET(n, p)	((p)->fds_bits[(n)/_NFDBITS] |= __fdset_mask(n))
+#define	FD_ZERO(p)	bzero(p, sizeof(*(p)))
 
 #ifndef _KERNEL
+struct timeval;
+
 __BEGIN_DECLS
 int pselect(int, fd_set *__restrict, fd_set *__restrict, fd_set *__restrict,
 	const struct timespec *__restrict, const sigset_t *__restrict);
+#ifndef _SELECT_DECLARED
+#define	_SELECT_DECLARED
+/* XXX missing restrict type-qualifier */
+int	select(int, fd_set *, fd_set *, fd_set *, struct timeval *);
+#endif
 __END_DECLS
 #endif /* !_KERNEL */
 
diff --git a/sys/sys/types.h b/sys/sys/types.h
index 6ceb747d9919..bd656ded073b 100644
--- a/sys/sys/types.h
+++ b/sys/sys/types.h
@@ -255,37 +255,22 @@ typedef	__timer_t	timer_t;
 #define	_TIMER_T_DECLARED
 #endif
 
+/*
+ * The following are all things that really shouldn't exist in this header,
+ * since its purpose is to provide typedefs, not miscellaneous doodads.
+ */
 #if __BSD_VISIBLE
+
+#include <sys/select.h>
+
+/* XXX should be moved to <sys/param.h>. */
 #define	NBBY	8		/* number of bits in a byte */
 
-/*
- * Select uses bit masks of file descriptors in longs.  These macros
- * manipulate such bit fields (the filesystem macros use chars).
- * FD_SETSIZE may be defined by the user, but the default here should
- * be enough for most uses.
- */
-#ifndef	FD_SETSIZE
-#define	FD_SETSIZE	1024U
-#endif
-
-typedef	unsigned long	fd_mask;
-#define	NFDBITS	(sizeof(fd_mask) * NBBY)	/* bits per mask */
-
+/* XXX should be removed, since <sys/param.h> has this. */
 #ifndef howmany
 #define	howmany(x, y)	(((x) + ((y) - 1U)) / (y))
 #endif
 
-typedef	struct fd_set {
-	fd_mask	fds_bits[howmany(FD_SETSIZE, NFDBITS)];
-} fd_set;
-
-#define	_fdset_mask(n)	((fd_mask)1 << ((n) % NFDBITS))
-#define	FD_SET(n, p)	((p)->fds_bits[(n)/NFDBITS] |= _fdset_mask(n))
-#define	FD_CLR(n, p)	((p)->fds_bits[(n)/NFDBITS] &= ~_fdset_mask(n))
-#define	FD_ISSET(n, p)	((p)->fds_bits[(n)/NFDBITS] & _fdset_mask(n))
-#define	FD_COPY(f, t)	bcopy(f, t, sizeof(*(f)))
-#define	FD_ZERO(p)	bzero(p, sizeof(*(p)))
-
 /*
  * These declarations belong elsewhere, but are repeated here and in
  * <stdio.h> to give broken programs a better chance of working with