diff --git a/MANIFEST b/MANIFEST
index d4c27925d..631048349 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -34,6 +34,7 @@ compat/mksiglist.c
 compat/mksiglist.h
 compat/mkstemp.c
 compat/nanosleep.c
+compat/setenv.c
 compat/siglist.in
 compat/snprintf.c
 compat/strcasecmp.c
@@ -42,6 +43,7 @@ compat/strlcat.c
 compat/strlcpy.c
 compat/strsignal.c
 compat/timespec.h
+compat/unsetenv.c
 compat/utime.h
 compat/utimes.c
 config.guess
diff --git a/aclocal.m4 b/aclocal.m4
index f42923a31..7a4bdca93 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -272,22 +272,6 @@ AC_DEFUN([SUDO_FUNC_UNSETENV_VOID],
     fi
   ])
 
-dnl
-dnl check putenv() argument for const
-dnl
-AC_DEFUN([SUDO_FUNC_PUTENV_CONST],
-[AC_CACHE_CHECK([whether putenv has a const argument],
-sudo_cv_func_putenv_const,
-[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([AC_INCLUDES_DEFAULT
-int putenv(const char *string) {return 0;}], [])],
-    [sudo_cv_func_putenv_const=yes],
-    [sudo_cv_func_putenv_const=no])
-  ])
-  if test $sudo_cv_func_putenv_const = yes; then
-    AC_DEFINE(PUTENV_CONST, 1, [Define to 1 if the `putenv' has a const argument.])
-  fi
-])
-
 dnl
 dnl check for sa_len field in struct sockaddr
 dnl
diff --git a/compat/setenv.c b/compat/setenv.c
new file mode 100644
index 000000000..a5c06e0fd
--- /dev/null
+++ b/compat/setenv.c
@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2010 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <config.h>
+
+#include <sys/types.h>
+
+#include <stdio.h>
+#ifdef STDC_HEADERS
+# include <stdlib.h>
+# include <stddef.h>
+#else
+# ifdef HAVE_STDLIB_H
+#  include <stdlib.h>
+# endif
+#endif /* STDC_HEADERS */
+#ifdef HAVE_STRING_H
+# include <string.h>
+#endif /* HAVE_STRING_H */
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif /* HAVE_STRINGS_H */
+#if defined(HAVE_MALLOC_H) && !defined(STDC_HEADERS)
+# include <malloc.h>
+#endif /* HAVE_MALLOC_H && !STDC_HEADERS */
+#include <errno.h>
+
+#include <compat.h>
+
+int
+setenv(const char *var, const char *val, int overwrite)
+{
+    char *envstr, *dst;
+    const char *src;
+    size_t esize;
+
+    if (!var || *var == '\0') {
+	errno = EINVAL;
+	return -1;
+    }
+
+    /*
+     * POSIX says a var name with '=' is an error but BSD
+     * just ignores the '=' and anything after it.
+     */
+    for (src = var; *src != '\0' && *src != '='; src++)
+	;
+    esize = (size_t)(src - var) + 2;
+    if (val) {
+        esize += strlen(val);	/* glibc treats a NULL val as "" */
+    }
+
+    /* Allocate and fill in envstr. */
+    if ((envstr = malloc(esize)) == NULL)
+	return -1;
+    for (src = var, dst = envstr; *src != '\0' && *src != '=';)
+	*dst++ = *src++;
+    *dst++ = '=';
+    if (val) {
+	for (src = val; *src != '\0';)
+	    *dst++ = *src++;
+    }
+    *dst = '\0';
+
+    if (!overwrite && getenv(var) != NULL) {
+	free(envstr);
+	return 0;
+    }
+    return putenv(envstr);
+}
diff --git a/compat/unsetenv.c b/compat/unsetenv.c
new file mode 100644
index 000000000..df4082922
--- /dev/null
+++ b/compat/unsetenv.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2010 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <config.h>
+
+#include <sys/types.h>
+
+#include <stdio.h>
+#ifdef STDC_HEADERS
+# include <stdlib.h>
+# include <stddef.h>
+#else
+# ifdef HAVE_STDLIB_H
+#  include <stdlib.h>
+# endif
+#endif /* STDC_HEADERS */
+#ifdef HAVE_STRING_H
+# include <string.h>
+#endif /* HAVE_STRING_H */
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif /* HAVE_STRINGS_H */
+#include <errno.h>
+
+#include <compat.h>
+
+extern char **environ;	/* global environment */
+
+#ifdef UNSETENV_VOID
+void
+#else
+int
+#endif
+unsetenv(const char *var)
+{
+    char **ep = environ;
+    size_t len;
+
+    if (var == NULL || *var == '\0' || strchr(var, '=') != NULL) {
+	errno = EINVAL;
+#ifdef UNSETENV_VOID
+	return;
+#else
+	return -1;
+#endif
+    }
+
+    len = strlen(var);
+    while (*ep != NULL) {
+	if (strncmp(var, *ep, len) == 0 && (*ep)[len] == '=') {
+	    /* Found it; shift remainder + NULL over by one. */
+	    char **cur = ep;
+	    while ((*cur = *(cur + 1)) != NULL)
+		cur++;
+	    /* Keep going, could be multiple instances of the var. */
+	} else {
+	    ep++;
+	}
+    }
+#ifndef UNSETENV_VOID
+    return 0;
+#endif
+}
diff --git a/configure b/configure
index 2a6f4dd6f..de1845f95 100755
--- a/configure
+++ b/configure
@@ -14764,7 +14764,7 @@ LIBS=$ac_save_LIBS
 
 for ac_func in strchr strrchr memchr memcpy memset sysconf tzset \
 	       strftime setrlimit initgroups fstat gettimeofday \
-	       regcomp setlocale getaddrinfo setenv vhangup \
+	       regcomp setlocale getaddrinfo vhangup \
 	       mbr_check_membership setrlimit64
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
@@ -15011,42 +15011,16 @@ $as_echo "#define UNSETENV_VOID 1" >>confdefs.h
 
     fi
 
+else
+  case " $LIBOBJS " in
+  *" unsetenv.$ac_objext "* ) ;;
+  *) LIBOBJS="$LIBOBJS unsetenv.$ac_objext"
+ ;;
+esac
+
 fi
 done
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether putenv has a const argument" >&5
-$as_echo_n "checking whether putenv has a const argument... " >&6; }
-if test "${sudo_cv_func_putenv_const+set}" = set; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-$ac_includes_default
-int putenv(const char *string) {return 0;}
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  sudo_cv_func_putenv_const=yes
-else
-  sudo_cv_func_putenv_const=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $sudo_cv_func_putenv_const" >&5
-$as_echo "$sudo_cv_func_putenv_const" >&6; }
-  if test $sudo_cv_func_putenv_const = yes; then
-
-$as_echo "#define PUTENV_CONST 1" >>confdefs.h
-
-  fi
-
 if test -z "$SKIP_SETRESUID"; then
     for ac_func in setresuid
 do :
@@ -15375,7 +15349,7 @@ esac
 
   fi
 
-for ac_func in memrchr strerror strcasecmp strlcpy strlcat
+for ac_func in memrchr strerror strcasecmp strlcpy strlcat setenv
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/configure.in b/configure.in
index fa5d65d3f..b818b7c8b 100644
--- a/configure.in
+++ b/configure.in
@@ -1916,7 +1916,7 @@ dnl
 AC_FUNC_GETGROUPS
 AC_CHECK_FUNCS(strchr strrchr memchr memcpy memset sysconf tzset \
 	       strftime setrlimit initgroups fstat gettimeofday \
-	       regcomp setlocale getaddrinfo setenv vhangup \
+	       regcomp setlocale getaddrinfo vhangup \
 	       mbr_check_membership setrlimit64)
 AC_CHECK_FUNCS(getline, [], [
     AC_LIBOBJ(getline)
@@ -1939,8 +1939,7 @@ AC_CHECK_FUNCS(openpty, [AC_CHECK_HEADERS(util.h pty.h, [break])], [
 	])
     ])
 ])
-AC_CHECK_FUNCS(unsetenv, SUDO_FUNC_UNSETENV_VOID)
-SUDO_FUNC_PUTENV_CONST
+AC_CHECK_FUNCS(unsetenv, [SUDO_FUNC_UNSETENV_VOID], [AC_LIBOBJ(unsetenv)])
 if test -z "$SKIP_SETRESUID"; then
     AC_CHECK_FUNCS(setresuid, [
 	SKIP_SETREUID=yes
@@ -1970,7 +1969,7 @@ AC_CHECK_FUNCS(utimes, [AC_CHECK_FUNCS(futimes futimesat, [break])], [AC_CHECK_F
 AC_CHECK_FUNCS(killpg, [], [AC_LIBOBJ(killpg)])
 SUDO_FUNC_FNMATCH([AC_DEFINE(HAVE_FNMATCH)], [AC_LIBOBJ(fnmatch)])
 SUDO_FUNC_ISBLANK
-AC_REPLACE_FUNCS(memrchr strerror strcasecmp strlcpy strlcat)
+AC_REPLACE_FUNCS(memrchr strerror strcasecmp strlcpy strlcat setenv)
 AC_CHECK_FUNCS(nanosleep, [], [
     # On Solaris, nanosleep is in librt
     AC_CHECK_LIB(rt, nanosleep, [REPLAY_LIBS="${REPLAY_LIBS} -lrt"], [AC_LIBOBJ(nanosleep)])
diff --git a/plugins/sudoers/env.c b/plugins/sudoers/env.c
index b956eeb32..637b854d3 100644
--- a/plugins/sudoers/env.c
+++ b/plugins/sudoers/env.c
@@ -255,134 +255,6 @@ sudo_setenv(const char *var, const char *val, int dupcheck)
     sudo_putenv(estring, dupcheck, TRUE);
 }
 
-/*
- * Version of getenv(3) that uses our own environ pointer.
- */
-char *
-getenv(const char *var)
-{
-    char *cp, **ev;
-    size_t vlen = strlen(var);
-
-    for (ev = env.envp; (cp = *ev) != NULL; ev++) {
-	if (strncmp(var, cp, vlen) == 0 && cp[vlen] == '=')
-	    return cp + vlen + 1;
-    }
-    return NULL;
-}
-
-/*
- * Version of setenv(3) that uses our own environ pointer.
- */
-int
-setenv(const char *var, const char *val, int overwrite)
-{
-    char *estring, *ep;
-    const char *cp;
-    size_t esize;
-
-    if (!var || *var == '\0') {
-	errno = EINVAL;
-	return -1;
-    }
-
-    /*
-     * POSIX says a var name with '=' is an error but BSD
-     * just ignores the '=' and anything after it.
-     */
-    for (cp = var; *cp && *cp != '='; cp++)
-	;
-    esize = (size_t)(cp - var) + 2;
-    if (val) {
-	esize += strlen(val);	/* glibc treats a NULL val as "" */
-    }
-
-    /* Allocate and fill in estring. */
-    estring = ep = emalloc(esize);
-    for (cp = var; *cp && *cp != '='; cp++)
-	*ep++ = *cp;
-    *ep++ = '=';
-    if (val) {
-	for (cp = val; *cp; cp++)
-	    *ep++ = *cp;
-    }
-    *ep = '\0';
-
-#ifdef ENV_DEBUG
-    if (env.envp[env.env_len] != NULL)
-	errorx(1, "setenv: corrupted envp, len mismatch");
-#endif
-    sudo_putenv(estring, TRUE, overwrite);
-    return 0;
-}
-
-/*
- * Version of unsetenv(3) that uses our own environ pointer.
- */
-#ifdef UNSETENV_VOID
-void
-#else
-int
-#endif
-unsetenv(const char *var)
-{
-    char **ep = env.envp;
-    size_t len;
-
-    if (var == NULL || *var == '\0' || strchr(var, '=') != NULL) {
-	errno = EINVAL;
-#ifdef UNSETENV_VOID
-	return;
-#else
-	return -1;
-#endif
-    }
-
-#ifdef ENV_DEBUG
-    if (env.envp[env.env_len] != NULL)
-	errorx(1, "unsetenv: corrupted envp, len mismatch");
-#endif
-
-    len = strlen(var);
-    while (*ep != NULL) {
-	if (strncmp(var, *ep, len) == 0 && (*ep)[len] == '=') {
-	    /* Found it; shift remainder + NULL over by one. */
-	    char **cur = ep;
-	    while ((*cur = *(cur + 1)) != NULL)
-		cur++;
-	    /* Keep going, could be multiple instances of the var. */
-	} else {
-	    ep++;
-	}
-    }
-    env.env_len = ep - env.envp;
-#ifndef UNSETENV_VOID
-    return 0;
-#endif
-}
-
-/*
- * Version of putenv(3) that uses our own environ pointer.
- */
-int
-#ifdef PUTENV_CONST
-putenv(const char *string)
-#else
-putenv(char *string)
-#endif
-{
-    if (strchr(string, '=') == NULL) {
-	errno = EINVAL;
-	return -1;
-    }
-#ifdef ENV_DEBUG
-    if (env.envp[env.env_len] != NULL)
-	errorx(1, "putenv: corrupted envp, len mismatch");
-#endif
-    sudo_putenv((char *)string, TRUE, TRUE);
-    return 0;
-}
-
 /*
  * Similar to putenv(3) but operates on sudo's private copy of the
  * environment (not environ) and it always overwrites.  The dupcheck param