diff --git a/src/include/stdlib.h b/src/include/stdlib.h
index 496090a5..840d381a 100644
--- a/src/include/stdlib.h
+++ b/src/include/stdlib.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: stdlib.h,v 1.45 2008/09/07 20:36:07 martynas Exp $	*/
+/*	$OpenBSD: stdlib.h,v 1.46 2009/06/03 15:52:16 millert Exp $	*/
 /*	$NetBSD: stdlib.h,v 1.25 1995/12/27 21:19:08 jtc Exp $	*/
 
 /*-
@@ -164,7 +164,7 @@ long	 nrand48(unsigned short[3]);
 unsigned short *seed48(unsigned short[3]);
 void	 srand48(long);
 
-int	 putenv(const char *);
+int	 putenv(char *);
 #endif
 
 #if __BSD_VISIBLE || __XPG_VISIBLE >= 420
@@ -210,7 +210,7 @@ unsigned long long
  */
 #if __BSD_VISIBLE || __POSIX_VISIBLE >= 200112 || __XPG_VISIBLE >= 600
 int	 setenv(const char *, const char *, int);
-void	 unsetenv(const char *);
+int	 unsetenv(const char *);
 #endif
 
 #if __BSD_VISIBLE
diff --git a/src/lib/libc/stdlib/Makefile.inc b/src/lib/libc/stdlib/Makefile.inc
index c149aeef..3b9b36a1 100644
--- a/src/lib/libc/stdlib/Makefile.inc
+++ b/src/lib/libc/stdlib/Makefile.inc
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile.inc,v 1.41 2008/09/13 22:48:45 martynas Exp $
+#	$OpenBSD: Makefile.inc,v 1.42 2009/06/03 15:52:16 millert Exp $
 
 # stdlib sources
 .PATH: ${LIBCSRCDIR}/arch/${MACHINE_ARCH}/stdlib ${LIBCSRCDIR}/stdlib
@@ -6,7 +6,7 @@
 SRCS+=	a64l.c abort.c atexit.c atoi.c atof.c atol.c atoll.c bsearch.c \
 	cfree.c exit.c ecvt.c gcvt.c getenv.c getopt_long.c \
 	getsubopt.c hcreate.c heapsort.c imaxabs.c imaxdiv.c l64a.c llabs.c \
-	lldiv.c lsearch.c malloc.c merge.c putenv.c qsort.c radixsort.c rand.c \
+	lldiv.c lsearch.c malloc.c merge.c qsort.c radixsort.c rand.c \
 	random.c realpath.c setenv.c strtoimax.c strtol.c \
 	strtoll.c strtonum.c strtoul.c strtoull.c strtoumax.c system.c \
 	tfind.c tsearch.c _rand48.c drand48.c erand48.c jrand48.c lcong48.c \
diff --git a/src/lib/libc/stdlib/getenv.3 b/src/lib/libc/stdlib/getenv.3
index 1d854699..484ff991 100644
--- a/src/lib/libc/stdlib/getenv.3
+++ b/src/lib/libc/stdlib/getenv.3
@@ -29,9 +29,9 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: getenv.3,v 1.12 2007/05/31 19:19:31 jmc Exp $
+.\"	$OpenBSD: getenv.3,v 1.13 2009/06/03 15:52:16 millert Exp $
 .\"
-.Dd $Mdocdate: May 31 2007 $
+.Dd $Mdocdate: June 3 2009 $
 .Dt GETENV 3
 .Os
 .Sh NAME
@@ -47,8 +47,8 @@
 .Ft int
 .Fn setenv "const char *name" "const char *value" "int overwrite"
 .Ft int
-.Fn putenv "const char *string"
-.Ft void
+.Fn putenv "char *string"
+.Ft int
 .Fn unsetenv "const char *name"
 .Sh DESCRIPTION
 These functions set, unset, and fetch environment variables from the host
@@ -87,11 +87,20 @@ is zero, the variable is not reset, otherwise it is reset to the given
 The
 .Fn putenv
 function takes an argument of the form
-.Ar name Ns = Ns Ar value
-and is equivalent to:
-.Bd -literal -offset indent
-setenv(name, value, 1);
-.Ed
+.Ar name Ns = Ns Ar value .
+The memory pointed to by
+.Ar string
+becomes part of the environment and must not be deallocated by the caller.
+If the variable already exists, it will be overwritten.
+A common source of bugs is to pass a
+.Ar string
+argument that is a locally scoped string buffer.
+This will result in corruption of the environment after leaving
+the scope in which the variable is defined.
+For this reason, the
+.Fn setenv
+function is preferred over
+.Fn putenv .
 .Pp
 The
 .Fn unsetenv
@@ -99,10 +108,7 @@ function deletes all instances of the variable name pointed to by
 .Fa name
 from the list.
 .Sh RETURN VALUES
-The functions
-.Fn setenv
-and
-.Fn putenv
+These functions
 return zero if successful; otherwise the global variable
 .Va errno
 is set to indicate the error and \-1 is returned.
@@ -112,12 +118,30 @@ If
 is successful, the string returned should be considered read-only.
 .Sh ERRORS
 .Bl -tag -width Er
+.It Bq Er EINVAL
+The
+.Fn setenv
+or
+.Fn putenv
+function was passed a
+.Ar name
+containing an
+.Sq =
+character.
+.Pp
+The
+.Fn putenv
+function was passed a
+.Ar string
+that did not contain an
+.Sq =
+character.
 .It Bq Er ENOMEM
-The function
+The
 .Fn setenv
 or
 .Fn putenv
-failed because they were unable to allocate memory for the environment.
+function failed because it was unable to allocate memory for the environment.
 .El
 .Sh SEE ALSO
 .Xr csh 1 ,
diff --git a/src/lib/libc/stdlib/getenv.c b/src/lib/libc/stdlib/getenv.c
index 72367b34..5aff11c6 100644
--- a/src/lib/libc/stdlib/getenv.c
+++ b/src/lib/libc/stdlib/getenv.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: getenv.c,v 1.8 2005/08/08 08:05:36 espie Exp $ */
+/*	$OpenBSD: getenv.c,v 1.9 2009/06/03 15:52:16 millert Exp $ */
 /*
  * Copyright (c) 1987, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -31,7 +31,7 @@
 #include <stdlib.h>
 #include <string.h>
 
-char *__findenv(const char *name, int *offset);
+char *__findenv(const char *name, int len, int *offset);
 
 /*
  * __findenv --
@@ -43,18 +43,15 @@ char *__findenv(const char *name, int *offset);
  *	This routine *should* be a static; don't use it.
  */
 char *
-__findenv(const char *name, int *offset)
+__findenv(const char *name, int len, int *offset)
 {
 	extern char **environ;
-	int len, i;
+	int i;
 	const char *np;
 	char **p, *cp;
 
 	if (name == NULL || environ == NULL)
 		return (NULL);
-	for (np = name; *np && *np != '='; ++np)
-		;
-	len = np - name;
 	for (p = environ; (cp = *p) != NULL; ++p) {
 		for (np = name, i = len; i && *cp; i--)
 			if (*cp++ != *np++)
@@ -75,6 +72,9 @@ char *
 getenv(const char *name)
 {
 	int offset;
+	const char *np;
 
-	return (__findenv(name, &offset));
+	for (np = name; *np && *np != '='; ++np)
+		;
+	return (__findenv(name, (int)(np - name), &offset));
 }
diff --git a/src/lib/libc/stdlib/putenv.c b/src/lib/libc/stdlib/putenv.c
deleted file mode 100644
index 54482f6a..00000000
--- a/src/lib/libc/stdlib/putenv.c
+++ /dev/null
@@ -1,50 +0,0 @@
-/*	$OpenBSD: putenv.c,v 1.5 2005/08/08 08:05:37 espie Exp $ */
-/*-
- * Copyright (c) 1988, 1993
- *     The Regents of the University of California.  All rights reserved.
- *
- * 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.
- */
-
-#include <stdlib.h>
-#include <string.h>
-
-int
-putenv(const char *str)
-{
-	char *p, *equal;
-	int rval;
-
-	if ((p = strdup(str)) == NULL)
-		return (-1);
-	if ((equal = strchr(p, '=')) == NULL) {
-		(void)free(p);
-		return (-1);
-	}
-	*equal = '\0';
-	rval = setenv(p, equal + 1, 1);
-	(void)free(p);
-	return (rval);
-}
diff --git a/src/lib/libc/stdlib/setenv.c b/src/lib/libc/stdlib/setenv.c
index 36540ebb..242830d7 100644
--- a/src/lib/libc/stdlib/setenv.c
+++ b/src/lib/libc/stdlib/setenv.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: setenv.c,v 1.9 2005/08/08 08:05:37 espie Exp $ */
+/*	$OpenBSD: setenv.c,v 1.10 2009/06/03 15:52:16 millert Exp $ */
 /*
  * Copyright (c) 1987 Regents of the University of California.
  * All rights reserved.
@@ -28,12 +28,53 @@
  * SUCH DAMAGE.
  */
 
+#include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 
-char *__findenv(const char *name, int *offset);
+char *__findenv(const char *name, int len, int *offset);
 
 extern char **environ;
+static char **lastenv;				/* last value of environ */
+
+/*
+ * putenv --
+ *	Add a name=value string directly to the environmental, replacing
+ *	any current value.
+ */
+int
+putenv(char *str)
+{
+	char **P, *cp;
+	size_t cnt;
+	int offset;
+
+	for (cp = str; *cp && *cp != '='; ++cp)
+		;
+	if (*cp != '=') {
+		errno = EINVAL;
+		return (-1);			/* missing `=' in string */
+	}
+
+	if (__findenv(str, (int)(cp - str), &offset) != NULL) {
+		environ[offset] = str;
+		return (0);
+	}
+
+	/* create new slot for string */
+	for (P = environ; *P != NULL; P++)
+		;
+	cnt = P - environ;
+	P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2));
+	if (!P)
+		return (-1);
+	if (lastenv != environ)
+		memcpy(P, environ, cnt * sizeof(char *));
+	lastenv = environ = P;
+	environ[cnt] = str;
+	environ[cnt + 1] = NULL;
+	return (0);
+}
 
 /*
  * setenv --
@@ -43,14 +84,21 @@ extern char **environ;
 int
 setenv(const char *name, const char *value, int rewrite)
 {
-	static char **lastenv;			/* last value of environ */
 	char *C;
+	const char *np;
 	int l_value, offset;
 
-	if (*value == '=')			/* no `=' in value */
-		++value;
+	for (np = name; *np && *np != '='; ++np)
+		;
+#ifdef notyet
+	if (*np) {
+		errno = EINVAL;
+		return (-1);			/* has `=' in name */
+	}
+#endif
+
 	l_value = strlen(value);
-	if ((C = __findenv(name, &offset))) {	/* find if already exists */
+	if ((C = __findenv(name, (int)(np - name), &offset)) != NULL) {
 		if (!rewrite)
 			return (0);
 		if (strlen(C) >= l_value) {	/* old larger; copy over */
@@ -74,10 +122,8 @@ setenv(const char *name, const char *value, int rewrite)
 		offset = cnt;
 		environ[cnt + 1] = NULL;
 	}
-	for (C = (char *)name; *C && *C != '='; ++C)
-		;				/* no `=' in name */
 	if (!(environ[offset] =			/* name + `=' + value */
-	    malloc((size_t)((int)(C - name) + l_value + 2))))
+	    malloc((size_t)((int)(np - name) + l_value + 2))))
 		return (-1);
 	for (C = environ[offset]; (*C = *name++) && *C != '='; ++C)
 		;
@@ -90,14 +136,25 @@ setenv(const char *name, const char *value, int rewrite)
  * unsetenv(name) --
  *	Delete environmental variable "name".
  */
-void
+int
 unsetenv(const char *name)
 {
 	char **P;
+	const char *np;
 	int offset;
 
-	while (__findenv(name, &offset))	/* if set multiple times */
+	for (np = name; *np && *np != '='; ++np)
+		;
+	if (*np) {
+		errno = EINVAL;
+		return (-1);			/* has `=' in name */
+	}
+
+	/* could be set multiple times */
+	while (__findenv(name, (int)(np - name), &offset)) {
 		for (P = &environ[offset];; ++P)
 			if (!(*P = *(P + 1)))
 				break;
+	}
+	return (0);
 }