diff --git a/include/bitstring.h b/include/bitstring.h
index eafdba18b098..cef9d0248d84 100644
--- a/include/bitstring.h
+++ b/include/bitstring.h
@@ -1,9 +1,6 @@
-/*
- * Copyright (c) 1989, 1993
- *	The Regents of the University of California.  All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * Paul Vixie.
+/*-
+ * Copyright (c) 2003 Poul-Henning Kamp
+ * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -13,18 +10,11 @@
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *	This product includes software developed by the University of
- *	California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
@@ -39,112 +29,7 @@
 #ifndef _BITSTRING_H_
 #define	_BITSTRING_H_
 
-typedef	unsigned char bitstr_t;
+#include <sys/bitstring.h>
 
-/* internal macros */
-				/* byte of the bitstring bit is in */
-#define	_bit_byte(bit) \
-	((bit) >> 3)
+#endif /* _BITSTRING_H_ */
 
-				/* mask for the bit within its byte */
-#define	_bit_mask(bit) \
-	(1 << ((bit)&0x7))
-
-/* external macros */
-				/* bytes in a bitstring of nbits bits */
-#define	bitstr_size(nbits) \
-	(((nbits) + 7) >> 3)
-
-				/* allocate a bitstring */
-#define	bit_alloc(nbits) \
-	(bitstr_t *)calloc((size_t)bitstr_size(nbits), sizeof(bitstr_t))
-
-				/* allocate a bitstring on the stack */
-#define	bit_decl(name, nbits) \
-	((name)[bitstr_size(nbits)])
-
-				/* is bit N of bitstring name set? */
-#define	bit_test(name, bit) \
-	((name)[_bit_byte(bit)] & _bit_mask(bit))
-
-				/* set bit N of bitstring name */
-#define	bit_set(name, bit) \
-	((name)[_bit_byte(bit)] |= _bit_mask(bit))
-
-				/* clear bit N of bitstring name */
-#define	bit_clear(name, bit) \
-	((name)[_bit_byte(bit)] &= ~_bit_mask(bit))
-
-				/* clear bits start ... stop in bitstring */
-#define	bit_nclear(name, start, stop) do { \
-	register bitstr_t *_name = (name); \
-	register int _start = (start), _stop = (stop); \
-	register int _startbyte = _bit_byte(_start); \
-	register int _stopbyte = _bit_byte(_stop); \
-	if (_startbyte == _stopbyte) { \
-		_name[_startbyte] &= ((0xff >> (8 - (_start&0x7))) | \
-				      (0xff << ((_stop&0x7) + 1))); \
-	} else { \
-		_name[_startbyte] &= 0xff >> (8 - (_start&0x7)); \
-		while (++_startbyte < _stopbyte) \
-			_name[_startbyte] = 0; \
-		_name[_stopbyte] &= 0xff << ((_stop&0x7) + 1); \
-	} \
-} while (0)
-
-				/* set bits start ... stop in bitstring */
-#define	bit_nset(name, start, stop) do { \
-	register bitstr_t *_name = (name); \
-	register int _start = (start), _stop = (stop); \
-	register int _startbyte = _bit_byte(_start); \
-	register int _stopbyte = _bit_byte(_stop); \
-	if (_startbyte == _stopbyte) { \
-		_name[_startbyte] |= ((0xff << (_start&0x7)) & \
-				    (0xff >> (7 - (_stop&0x7)))); \
-	} else { \
-		_name[_startbyte] |= 0xff << ((_start)&0x7); \
-		while (++_startbyte < _stopbyte) \
-	    		_name[_startbyte] = 0xff; \
-		_name[_stopbyte] |= 0xff >> (7 - (_stop&0x7)); \
-	} \
-} while (0)
-
-				/* find first bit clear in name */
-#define	bit_ffc(name, nbits, value) do { \
-	register bitstr_t *_name = (name); \
-	register int _byte, _nbits = (nbits); \
-	register int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \
-	if (_nbits > 0) \
-		for (_byte = 0; _byte <= _stopbyte; ++_byte) \
-			if (_name[_byte] != 0xff) { \
-				bitstr_t _lb; \
-				_value = _byte << 3; \
-				for (_lb = _name[_byte]; (_lb&0x1); \
-				    ++_value, _lb >>= 1); \
-				break; \
-			} \
-	if (_value >= nbits) \
-		_value = -1; \
-	*(value) = _value; \
-} while (0)
-
-				/* find first bit set in name */
-#define	bit_ffs(name, nbits, value) do { \
-	register bitstr_t *_name = (name); \
-	register int _byte, _nbits = (nbits); \
-	register int _stopbyte = _bit_byte(_nbits - 1), _value = -1; \
-	if (_nbits > 0) \
-		for (_byte = 0; _byte <= _stopbyte; ++_byte) \
-			if (_name[_byte]) { \
-				bitstr_t _lb; \
-				_value = _byte << 3; \
-				for (_lb = _name[_byte]; !(_lb&0x1); \
-				    ++_value, _lb >>= 1); \
-				break; \
-			} \
-	if (_value >= nbits) \
-		_value = -1; \
-	*(value) = _value; \
-} while (0)
-
-#endif /* !_BITSTRING_H_ */
diff --git a/sys/sys/bitstring.h b/sys/sys/bitstring.h
index eafdba18b098..e1e958a43393 100644
--- a/sys/sys/bitstring.h
+++ b/sys/sys/bitstring.h
@@ -36,8 +36,8 @@
  * $FreeBSD$
  */
 
-#ifndef _BITSTRING_H_
-#define	_BITSTRING_H_
+#ifndef _SYS_BITSTRING_H_
+#define	_SYS_BITSTRING_H_
 
 typedef	unsigned char bitstr_t;
 
@@ -147,4 +147,4 @@ typedef	unsigned char bitstr_t;
 	*(value) = _value; \
 } while (0)
 
-#endif /* !_BITSTRING_H_ */
+#endif /* !_SYS_BITSTRING_H_ */