diff --git a/libc/include/grp.h b/libc/include/grp.h
new file mode 100644
index 0000000..4efc2bd
--- /dev/null
+++ b/libc/include/grp.h
@@ -0,0 +1,79 @@
+/*	$OpenBSD: grp.h,v 1.8 2005/12/13 00:35:22 millert Exp $	*/
+/*	$NetBSD: grp.h,v 1.7 1995/04/29 05:30:40 cgd Exp $	*/
+
+/*-
+ * Copyright (c) 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * (c) UNIX System Laboratories, Inc.
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 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. 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
+ * 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
+ * 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)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)grp.h	8.2 (Berkeley) 1/21/94
+ */
+
+#ifndef _GRP_H_
+#define	_GRP_H_
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+#if __BSD_VISIBLE
+#define	_PATH_GROUP		"/etc/group"
+#endif
+
+struct group {
+	char	*gr_name;		/* group name */
+	char	*gr_passwd;		/* group password */
+	gid_t	gr_gid;			/* group id */
+	char	**gr_mem;		/* group members */
+};
+
+__BEGIN_DECLS
+struct group	*getgrgid(gid_t);
+struct group	*getgrnam(const char *);
+#if __BSD_VISIBLE || __POSIX_VISIBLE >= 200112 || __XPG_VISIBLE
+struct group	*getgrent(void);
+void		 setgrent(void);
+void		 endgrent(void);
+int		 getgrgid_r(gid_t, struct group *, char *,
+		    size_t, struct group **);
+int		 getgrnam_r(const char *, struct group *, char *,
+		    size_t, struct group **);
+#endif
+#if __BSD_VISIBLE
+void		 setgrfile(const char *);
+int		 setgroupent(int);
+char		*group_from_gid(gid_t, int);
+#endif
+
+int   getgrouplist (const char *user, gid_t group,
+                  gid_t *groups, int *ngroups);
+__END_DECLS
+
+#endif /* !_GRP_H_ */