diff --git a/sys/include/envvars.h b/sys/include/envvars.h
new file mode 100644
index 0000000..65a3ad5
--- /dev/null
+++ b/sys/include/envvars.h
@@ -0,0 +1,44 @@
+/*
+ * This file is part of Jehanne.
+ *
+ * Copyright (C) 2017 Giacomo Tesio <giacomo@tesio.it>
+ *
+ * Jehanne is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * Jehanne is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Jehanne.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* This file defines the names of a few environment variables shared
+ * among the userspace tools provided by Jehanne.
+ *
+ * It must not provide defines for variables used by commonly installed
+ * softwares, just the one used by the core tools, the one required
+ * to boot a minimal system.
+ */
+
+#define ENV_APID	"apid"
+#define ENV_USER	"user"
+#define ENV_HOME	"home"
+#define ENV_IFS		"ifs"
+#define ENV_PATH	"path"
+#define ENV_PID		"pid"
+#define ENV_PROMPT	"prompt"
+#define ENV_STATUS	"status"
+#define ENV_CDPATH	"cdpath"
+#define ENV_CPUTYPE	"cputype"
+#define ENV_SERVICE	"service"
+#define ENV_SYSNAME	"sysname"
+#define ENV_OBJTYPE	"objtype"
+
+#define ENV_WSYS	"wsys"
+
+extern	char*	jehanne_getenv(const char*);
+extern	int	jehanne_putenv(const char*, const char*);
diff --git a/sys/include/libc.h b/sys/include/libc.h
index 31c504f..d8d81c9 100644
--- a/sys/include/libc.h
+++ b/sys/include/libc.h
@@ -325,7 +325,6 @@ extern	int	jehanne_encodefmt(Fmt*);
 extern	void	jehanne_exits(const char*) __attribute__ ((noreturn));
 extern	double	jehanne_frexp(double, int*);
 extern	uintptr_t	jehanne_getcallerpc(void);
-extern	char*	jehanne_getenv(const char*);
 extern	int	jehanne_getfields(char*, char**, int, int, const char*);
 extern	int	jehanne_gettokens(char *, char **, int, const char *);
 extern	char*	jehanne_getuser(void);
@@ -344,7 +343,6 @@ extern	void	jehanne_perror(const char*);
 extern	int	jehanne_pipe(int pipes[2]);
 extern	int	jehanne_postnote(int, int, const char *);
 extern	double	jehanne_pow10(int);
-extern	int	jehanne_putenv(const char*, const char*);
 extern	void	jehanne_qsort(void*, long, int,
 			int (*)(const void*, const void*));
 extern	void*	jehanne_bsearch(const void* key, const void* base, size_t nmemb, size_t size,
diff --git a/sys/src/cmd/acme/acme.c b/sys/src/cmd/acme/acme.c
index 1373d9d..e3b9c0f 100644
--- a/sys/src/cmd/acme/acme.c
+++ b/sys/src/cmd/acme/acme.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <draw.h>
 #include <thread.h>
 #include <cursor.h>
@@ -124,9 +125,9 @@ threadmain(int argc, char *argv[])
 	fontnames[1] = estrdup(fontnames[1]);
 
 	quotefmtinstall();
-	cputype = getenv("cputype");
-	objtype = getenv("objtype");
-	home = getenv("home");
+	cputype = getenv(ENV_CPUTYPE);
+	objtype = getenv(ENV_OBJTYPE);
+	home = getenv(ENV_HOME);
 	p = getenv("tabstop");
 	if(p != nil){
 		maxtab = strtoul(p, nil, 0);
diff --git a/sys/src/cmd/acme/aux/win/main.c b/sys/src/cmd/acme/aux/win/main.c
index c68b3a9..799168a 100644
--- a/sys/src/cmd/acme/aux/win/main.c
+++ b/sys/src/cmd/acme/aux/win/main.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <bio.h>
 #include <thread.h>
 #include <9P2000.h>
@@ -61,7 +62,7 @@ threadmain(int argc, char *argv[])
 		av = emalloc(3*sizeof(char*));
 		av[0] = "rc";
 		av[1] = "-i";
-		name = getenv("sysname");
+		name = getenv(ENV_SYSNAME);
 	}else{
 		av = argv;
 		name = utfrrune(av[0], '/');
diff --git a/sys/src/cmd/acme/exec.c b/sys/src/cmd/acme/exec.c
index f6ff946..911f37f 100644
--- a/sys/src/cmd/acme/exec.c
+++ b/sys/src/cmd/acme/exec.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <draw.h>
 #include <thread.h>
 #include <cursor.h>
diff --git a/sys/src/cmd/auth/as.c b/sys/src/cmd/auth/as.c
index 51a45cb..6bb4762 100644
--- a/sys/src/cmd/auth/as.c
+++ b/sys/src/cmd/auth/as.c
@@ -63,7 +63,7 @@ runas(char *user, char *cmd)
 {
 	if(becomeuser(user) < 0)
 		sysfatal("can't change uid for %s: %r", user);
-	putenv("service", "rx");
+	putenv(ENV_SERVICE, "rx");
 	execl("/bin/rc", "rc", "-lc", cmd, nil);
 	sysfatal("exec /bin/rc: %r");
 }
diff --git a/sys/src/cmd/auth/cron.c b/sys/src/cmd/auth/cron.c
index e8aa75e..8c5d4ab 100644
--- a/sys/src/cmd/auth/cron.c
+++ b/sys/src/cmd/auth/cron.c
@@ -568,7 +568,7 @@ rexec(User *user, Job *j)
 	open("/dev/null", OWRITE);
 
 	if(strcmp(j->host, "local") == 0){
-		putenv("service", "rx");
+		putenv(ENV_SERVICE, "rx");
 		execl("/bin/rc", "rc", "-lc", buf, nil);
 	} else {
 		execl("/bin/rx", "rx", j->host, buf, nil);
diff --git a/sys/src/cmd/auth/factotum/util.c b/sys/src/cmd/auth/factotum/util.c
index 6a19de4..25ead5d 100644
--- a/sys/src/cmd/auth/factotum/util.c
+++ b/sys/src/cmd/auth/factotum/util.c
@@ -1,3 +1,4 @@
+#include <envvars.h>
 #include "dat.h"
 
 //static char secstore[100];   /* server name */ // NOT USED
@@ -712,7 +713,7 @@ promptforhostowner(void)
 	char owner[64], *p;
 
 	/* hack for bitsy; can't prompt during boot */
-	if(p = getenv("user")){
+	if(p = getenv(ENV_USER)){
 		writehostowner(p);
 		free(p);
 		return;
diff --git a/sys/src/cmd/auth/login.c b/sys/src/cmd/auth/login.c
index a213438..c61185c 100644
--- a/sys/src/cmd/auth/login.c
+++ b/sys/src/cmd/auth/login.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <auth.h>
 #include <authsrv.h>
 #include <bio.h>
@@ -70,10 +71,12 @@ void
 setenv(char *var, char *val)
 {
 	int fd;
+	char buf[128+4];
 
-	fd = ocreate(var, OWRITE, 0644);
+	snprint(buf, sizeof(buf), "#e/%s", var);
+	fd = ocreate(buf, OWRITE, 0644);
 	if(fd < 0)
-		print("init: can't open %s\n", var);
+		print("init: can't open %s\n", buf);
 	else{
 		fprint(fd, val);
 		close(fd);
@@ -126,7 +129,7 @@ getauthdom(void)
 	if(authdom != nil)
 		return authdom;
 
-	sysname = getenv("sysname");
+	sysname = getenv(ENV_SYSNAME);
 	if(sysname == nil)
 		return strdup("cs.bell-labs.com");
 
@@ -209,7 +212,7 @@ main(int argc, char *argv[])
 
 	rfork(RFENVG|RFNAMEG);
 
-	service = getenv("service");
+	service = getenv(ENV_SERVICE);
 	if(strcmp(service, "cpu") == 0)
 		fprint(2, "login: warning: running on a cpu server!\n");
 	if(argc != 1){
@@ -239,24 +242,23 @@ main(int argc, char *argv[])
 	mountfactotum(srvname);
 
 	/* set up a new environment */
-	cputype = getenv("cputype");
-	sysname = getenv("sysname");
+	cputype = getenv(ENV_CPUTYPE);
+	sysname = getenv(ENV_SYSNAME);
 	tz = getenv("timezone");
 	rfork(RFCENVG);
-	setenv("#e/service", "con");
-	setenv("#e/user", user);
+	setenv(ENV_SERVICE, "con");
+	setenv(ENV_USER, user);
 	snprint(home, sizeof(home), "/usr/%s", user);
-	setenv("#e/home", home);
-	setenv("#e/cputype", cputype);
-	setenv("#e/objtype", cputype);
+	setenv(ENV_HOME, home);
+	setenv(ENV_CPUTYPE, cputype);
+	setenv(ENV_OBJTYPE, cputype);
 	if(sysname != nil)
-		setenv("#e/sysname", sysname);
+		setenv(ENV_SYSNAME, sysname);
 	if(tz != nil)
-		setenv("#e/timezone", tz);
+		setenv("timezone", tz);
 
 	/* go to new home directory */
-	snprint(buf, sizeof(buf), "/usr/%s", user);
-	if(chdir(buf) < 0)
+	if(chdir(home) < 0)
 		chdir("/");
 
 	/* read profile and start interactive rc */
diff --git a/sys/src/cmd/auth/netkey.c b/sys/src/cmd/auth/netkey.c
index f5c6747..43f506b 100644
--- a/sys/src/cmd/auth/netkey.c
+++ b/sys/src/cmd/auth/netkey.c
@@ -26,7 +26,7 @@ main(int argc, char *argv[])
 	if(argc)
 		usage();
 
-	s = getenv("service");
+	s = getenv(ENV_SERVICE);
 	if(s && strcmp(s, "cpu") == 0){
 		fprint(2, "netkey must not be run on the cpu server\n");
 		exits("boofhead");
diff --git a/sys/src/cmd/auth/secstore/secchk.c b/sys/src/cmd/auth/secstore/secchk.c
index 4c138b3..4157487 100644
--- a/sys/src/cmd/auth/secstore/secchk.c
+++ b/sys/src/cmd/auth/secstore/secchk.c
@@ -25,7 +25,7 @@ main(int argc, char **argv)
 		syslog(0, "secstore", "no /lib/ndb/local");
 	db = ndbcat(db, db2);
 
-	print("user=%s\n", getenv("user"));
-	print("%s\n", secureidcheck(getenv("user"), argv[1]));
+	print("%s=%s\n", ENV_USER, getenv(ENV_USER));
+	print("%s\n", secureidcheck(getenv(ENV_USER), argv[1]));
 	exits(0);
 }
diff --git a/sys/src/cmd/awk/tran.c b/sys/src/cmd/awk/tran.c
index a911145..1917f5e 100644
--- a/sys/src/cmd/awk/tran.c
+++ b/sys/src/cmd/awk/tran.c
@@ -24,6 +24,7 @@ THIS SOFTWARE.
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <ctype.h>
 #include <bio.h>
 #include "awk.h"
diff --git a/sys/src/cmd/cpu.c b/sys/src/cmd/cpu.c
index e2df8f1..5648e5a 100644
--- a/sys/src/cmd/cpu.c
+++ b/sys/src/cmd/cpu.c
@@ -16,6 +16,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <bio.h>
 #include <auth.h>
 #include <9P2000.h>
@@ -301,7 +302,7 @@ remoteside(int old)
 	int i, n, fd, badchdir, gotcmd;
 
 	rfork(RFENVG);
-	putenv("service", "cpu");
+	putenv(ENV_SERVICE, "cpu");
 	fd = 0;
 
 	/* negotiate authentication mechanism */
@@ -319,9 +320,9 @@ remoteside(int old)
 		fatal(1, "srvauth");
 
 	/* Set environment values for the user */
-	putenv("user", user);
+	putenv(ENV_USER, user);
 	sprint(home, "/usr/%s", user);
-	putenv("home", home);
+	putenv(ENV_HOME, home);
 
 	/* Now collect invoking cpu's current directory or possibly a command */
 	gotcmd = 0;
diff --git a/sys/src/cmd/disk/mkfs.c b/sys/src/cmd/disk/mkfs.c
index ee00621..723d474 100644
--- a/sys/src/cmd/disk/mkfs.c
+++ b/sys/src/cmd/disk/mkfs.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <disk.h>
 #include <auth.h>
 #include <bio.h>
@@ -115,7 +116,7 @@ main(int argc, char **argv)
 	zbuf = malloc(buflen);
 	memset(zbuf, 0, buflen);
 
-	cputype = getenv("cputype");
+	cputype = getenv(ENV_CPUTYPE);
 	if(cputype == 0)
 		cputype = "386";
 
diff --git a/sys/src/cmd/exportfs/exportfs.c b/sys/src/cmd/exportfs/exportfs.c
index 7042f1b..253d60f 100644
--- a/sys/src/cmd/exportfs/exportfs.c
+++ b/sys/src/cmd/exportfs/exportfs.c
@@ -12,6 +12,7 @@
  */
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <auth.h>
 #include <9P2000.h>
 #include <libsec.h>
@@ -213,7 +214,7 @@ main(int argc, char **argv)
 			fatal("exportfs by none disallowed");
 		if(auth_chuid(ai, nsfile) < 0)
 			fatal("auth_chuid: %r");
-		putenv("service", "exportfs");
+		putenv(ENV_SERVICE, "exportfs");
 	}
 
 	if(srvfdfile){
diff --git a/sys/src/cmd/hget.c b/sys/src/cmd/hget.c
index d33b21f..0e6451e 100644
--- a/sys/src/cmd/hget.c
+++ b/sys/src/cmd/hget.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <ctype.h>
 #include <bio.h>
 #include <ip.h>
diff --git a/sys/src/cmd/hmi/vga/main.c b/sys/src/cmd/hmi/vga/main.c
index 19324cb..35740ec 100644
--- a/sys/src/cmd/hmi/vga/main.c
+++ b/sys/src/cmd/hmi/vga/main.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <bio.h>
 
 #include "pci.h"
diff --git a/sys/src/cmd/import.c b/sys/src/cmd/import.c
index 2b39370..6cd5cb8 100644
--- a/sys/src/cmd/import.c
+++ b/sys/src/cmd/import.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <auth.h>
 #include <libsec.h>
 
@@ -363,7 +364,7 @@ passive(void)
 		sysfatal("auth_proxy: %r");
 	if(auth_chuid(ai, nil) < 0)
 		sysfatal("auth_chuid: %r");
-	putenv("service", "import");
+	putenv(ENV_SERVICE, "import");
 
 	fd = dup(0, -1);
 	close(0);
diff --git a/sys/src/cmd/ip/dhcpclient.c b/sys/src/cmd/ip/dhcpclient.c
index 4797bf6..b91c258 100644
--- a/sys/src/cmd/ip/dhcpclient.c
+++ b/sys/src/cmd/ip/dhcpclient.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <ip.h>
 #include "dhcp.h"
 
@@ -210,6 +211,7 @@ void
 dhcpinit(void)
 {
 	int fd;
+	char *sysname;
 
 	dhcp.state = Sinit;
 	dhcp.timeout = 4;
@@ -222,7 +224,9 @@ dhcpinit(void)
 		dhcp.xid = time(0)*getpid();
 	srand(dhcp.xid);
 
-	sprint(dhcp.cid, "%s.%d", getenv("sysname"), getpid());
+	sysname = getenv(ENV_SYSNAME);
+	sprint(dhcp.cid, "%s.%d", sysname, getpid());
+	free(sysname);
 }
 
 void
diff --git a/sys/src/cmd/ip/dhcpd/dhcpd.c b/sys/src/cmd/ip/dhcpd/dhcpd.c
index d0cb965..715219f 100644
--- a/sys/src/cmd/ip/dhcpd/dhcpd.c
+++ b/sys/src/cmd/ip/dhcpd/dhcpd.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <ip.h>
 #include <bio.h>
 #include <ndb.h>
@@ -1360,7 +1361,7 @@ readsysname(void)
 			return name;
 		}
 	}
-	p = getenv("sysname");
+	p = getenv(ENV_SYSNAME);
 	if(p == nil || *p == 0)
 		return "unknown";
 	return p;
diff --git a/sys/src/cmd/ip/ipconfig/main.c b/sys/src/cmd/ip/ipconfig/main.c
index d057674..b7874ed 100644
--- a/sys/src/cmd/ip/ipconfig/main.c
+++ b/sys/src/cmd/ip/ipconfig/main.c
@@ -3,6 +3,7 @@
  */
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <ip.h>
 #include <bio.h>
 #include <ndb.h>
@@ -390,7 +391,7 @@ init(void)
  	nsec();			/* make sure time file is open before forking */
 
 	setnetmtpt(conf.mpoint, sizeof conf.mpoint, nil);
-	conf.cputype = getenv("cputype");
+	conf.cputype = getenv(ENV_CPUTYPE);
 	if(conf.cputype == nil)
 		conf.cputype = "386";
 
@@ -410,7 +411,7 @@ parseargs(int argc, char **argv)
 
 	/* default to any host name we already have */
 	if(*conf.hostname == 0){
-		p = getenv("sysname");
+		p = getenv(ENV_SYSNAME);
 		if(p == nil || *p == 0)
 			p = sysname();
 		if(p != nil)
diff --git a/sys/src/cmd/ip/listen.c b/sys/src/cmd/ip/listen.c
index 638a9b3..4f1dec5 100644
--- a/sys/src/cmd/ip/listen.c
+++ b/sys/src/cmd/ip/listen.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <auth.h>
 
 #define	NAMELEN	64	/* reasonable upper limit for name elements */
@@ -97,7 +98,7 @@ main(int argc, char *argv[])
 	quiet = 0;
 	immutable = 0;
 	argv0 = argv[0];
-	cpu = getenv("cputype");
+	cpu = getenv(ENV_CPUTYPE);
 	if(cpu == 0)
 		error("can't get cputype");
 
diff --git a/sys/src/cmd/ip/listen1.c b/sys/src/cmd/ip/listen1.c
index 360f73a..a35d48b 100644
--- a/sys/src/cmd/ip/listen1.c
+++ b/sys/src/cmd/ip/listen1.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <auth.h>
 
 int verbose;
diff --git a/sys/src/cmd/ip/timesync.c b/sys/src/cmd/ip/timesync.c
index 4984979..67c71fd 100644
--- a/sys/src/cmd/ip/timesync.c
+++ b/sys/src/cmd/ip/timesync.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <auth.h>
 #include <ip.h>
 #include <mp.h>
@@ -249,7 +250,7 @@ main(int argc, char **argv)
 	fmtinstall('E', eipfmt);
 	fmtinstall('I', eipfmt);
 	fmtinstall('V', eipfmt);
-	sysid = getenv("sysname");
+	sysid = getenv(ENV_SYSNAME);
 
 	/* detach from the current namespace */
 	if(debug)
diff --git a/sys/src/cmd/mc.c b/sys/src/cmd/mc.c
index d85269d..57e4e20 100644
--- a/sys/src/cmd/mc.c
+++ b/sys/src/cmd/mc.c
@@ -16,10 +16,11 @@
  *	-t suppresses expanding multiple blanks into tabs
  *
  */
-#include	<u.h>
-#include	<lib9.h>
-#include	<draw.h>
-#include	<bio.h>
+#include <u.h>
+#include <lib9.h>
+#include <envvars.h>
+#include <draw.h>
+#include <bio.h>
 
 #define	WIDTH			80
 #define	TAB	4
diff --git a/sys/src/cmd/ndb/cs.c b/sys/src/cmd/ndb/cs.c
index 2be341c..e5455af 100644
--- a/sys/src/cmd/ndb/cs.c
+++ b/sys/src/cmd/ndb/cs.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <auth.h>
 #include <9P2000.h>
 #include <bio.h>
@@ -1032,7 +1033,7 @@ ipid(void)
 		 *  is the ip address.  ignore that.
 		 *
 		 */
-		p = getenv("sysname");
+		p = getenv(ENV_SYSNAME);
 		if(p && *p){
 			attr = ipattr(p);
 			if(strcmp(attr, "ip") != 0)
diff --git a/sys/src/cmd/ndb/dblookup.c b/sys/src/cmd/ndb/dblookup.c
index e10a9b4..6cd40b7 100644
--- a/sys/src/cmd/ndb/dblookup.c
+++ b/sys/src/cmd/ndb/dblookup.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <bio.h>
 #include <ndb.h>
 #include <ip.h>
diff --git a/sys/src/cmd/ndb/inform.c b/sys/src/cmd/ndb/inform.c
index 56340af..6da572c 100644
--- a/sys/src/cmd/ndb/inform.c
+++ b/sys/src/cmd/ndb/inform.c
@@ -1,6 +1,7 @@
 /* RFC2136 DNS inform - necessary for Win2k3 DNS servers */
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <bio.h>
 #include <ndb.h>
 #include <ip.h>
@@ -123,8 +124,8 @@ main(int argc, char *argv[])
 	if(argc != 0)
 		usage();
 
-	if((sysname = getenv("sysname")) == nil)
-		sysfatal("$sysname not set");
+	if((sysname = getenv(ENV_SYSNAME)) == nil)
+		sysfatal("$%s not set", ENV_SYSNAME);
 
 	if((db = ndbopen(nil)) == nil)
 		sysfatal("can't open ndb: %r");
diff --git a/sys/src/cmd/rc/rc.h b/sys/src/cmd/rc/rc.h
index 3b694d7..4314f04 100644
--- a/sys/src/cmd/rc/rc.h
+++ b/sys/src/cmd/rc/rc.h
@@ -8,16 +8,9 @@
  */
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 
 #define ENV_RCARGLIST	"*"
-#define ENV_APID	"apid"
-#define ENV_HOME	"home"
-#define ENV_IFS		"ifs"
-#define ENV_PATH	"path"
-#define ENV_PID		"pid"
-#define ENV_PROMPT	"prompt"
-#define ENV_STATUS	"status"
-#define ENV_CDPATH	"cdpath"
 #define ENV_RCNAME	"rcname"
 #define ENV_RCCMD	"rccmd"
 
diff --git a/sys/src/cmd/rio/fsys.c b/sys/src/cmd/rio/fsys.c
index 32eba12..302f537 100644
--- a/sys/src/cmd/rio/fsys.c
+++ b/sys/src/cmd/rio/fsys.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <draw.h>
 #include <thread.h>
 #include <cursor.h>
@@ -167,7 +168,7 @@ filsysinit(Channel *cxfidalloc)
 	 * Post srv pipe
 	 */
 	snprint(srvpipe, sizeof(srvpipe), "/srv/rio.%s.%d", fs->user, pid);
-	post(srvpipe, "wsys", fs->cfd);
+	post(srvpipe, ENV_WSYS, fs->cfd);
 
 	return fs;
 
diff --git a/sys/src/cmd/rio/rio.c b/sys/src/cmd/rio/rio.c
index 5324a90..2bd5040 100644
--- a/sys/src/cmd/rio/rio.c
+++ b/sys/src/cmd/rio/rio.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <draw.h>
 #include <thread.h>
 #include <cursor.h>
@@ -172,7 +173,7 @@ threadmain(int argc, char *argv[])
 		maxtab = 4;
 	free(s);
 
-	s = getenv("cputype");
+	s = getenv(ENV_CPUTYPE);
 	if(s){
 		snprint(buf, sizeof(buf), "/arch/%s/aux/rio", s);
 		bind(buf, "/cmd", MBEFORE);
diff --git a/sys/src/cmd/sam/plan9.c b/sys/src/cmd/sam/plan9.c
index adcc3cd..b58ac68 100644
--- a/sys/src/cmd/sam/plan9.c
+++ b/sys/src/cmd/sam/plan9.c
@@ -26,7 +26,6 @@ Rune *right[]= {
 
 char	RSAM[] = "sam";
 char	SAMTERM[] = "/cmd/aux/samterm";
-char	HOME[] = "home";
 char	TMPDIR[] = "/tmp";
 char	SH[] = "rc";
 char	SHPATH[] = "/cmd/rc";
diff --git a/sys/src/cmd/sam/sam.c b/sys/src/cmd/sam/sam.c
index dbd32d8..dd80f52 100644
--- a/sys/src/cmd/sam/sam.c
+++ b/sys/src/cmd/sam/sam.c
@@ -83,7 +83,7 @@ void main(int argc, char *argv[])
 	Strinit0(&rhs);
 	Strinit0(&curwd);
 	Strinit0(&plan9cmd);
-	home = getenv(HOME);
+	home = getenv(ENV_HOME);
 	disk = diskinit();
 	if(home == 0)
 		home = "/";
diff --git a/sys/src/cmd/sam/sam.h b/sys/src/cmd/sam/sam.h
index f5bb293..cd9ed71 100644
--- a/sys/src/cmd/sam/sam.h
+++ b/sys/src/cmd/sam/sam.h
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <plumb.h>
 #include "errors.h"
 
@@ -353,7 +354,6 @@ extern Rune	*right[];
 
 extern char	RSAM[];		/* system dependent */
 extern char	SAMTERM[];
-extern char	HOME[];
 extern char	TMPDIR[];
 extern char	SH[];
 extern char	SHPATH[];
diff --git a/sys/src/cmd/samterm/plan9.c b/sys/src/cmd/samterm/plan9.c
index 9f708e0..e119999 100644
--- a/sys/src/cmd/samterm/plan9.c
+++ b/sys/src/cmd/samterm/plan9.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <libc.h>
+#include <envvars.h>
 #include <draw.h>
 #include <thread.h>
 #include <mouse.h>
diff --git a/sys/src/cmd/stats.c b/sys/src/cmd/stats.c
index 56681ab..5f78960 100644
--- a/sys/src/cmd/stats.c
+++ b/sys/src/cmd/stats.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <ctype.h>
 #include <draw.h>
 #include <event.h>
@@ -1236,7 +1237,7 @@ main(int argc, char *argv[])
 	quotefmtinstall();
 
 	nmach = 1;
-	mysysname = getenv("sysname");
+	mysysname = getenv(ENV_SYSNAME);
 	if(mysysname == nil){
 		fprint(2, "stats: can't find $sysname: %r\n");
 		exits("sysname");
diff --git a/sys/src/kern/amd64/main.c b/sys/src/kern/amd64/main.c
index 1c6f14b..eb45f9d 100644
--- a/sys/src/kern/amd64/main.c
+++ b/sys/src/kern/amd64/main.c
@@ -22,6 +22,7 @@
 #include "fns.h"
 #include "ureg.h"
 #include "pool.h"
+#include "envvars.h"
 
 #include "io.h"
 #include "apic.h"
@@ -374,11 +375,11 @@ init0(void)
 		jehanne_snprint(buf, sizeof(buf), "%s %s", "AMD64", conffile);
 		loadenv(oargc, oargv);
 		ksetenv("terminal", buf, 0);
-		ksetenv("cputype", "amd64", 0);
+		ksetenv(ENV_CPUTYPE, "amd64", 0);
 		if(cpuserver)
-			ksetenv("service", "cpu", 0);
+			ksetenv(ENV_SERVICE, "cpu", 0);
 		else
-			ksetenv("service", "terminal", 0);
+			ksetenv(ENV_SERVICE, "terminal", 0);
 		poperror();
 	}
 	kproc("alarm", alarmkproc, 0);
diff --git a/sys/src/kern/boot/boot.c b/sys/src/kern/boot/boot.c
index b420152..6a039a1 100644
--- a/sys/src/kern/boot/boot.c
+++ b/sys/src/kern/boot/boot.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <libc.h>
+#include <envvars.h>
 #include <auth.h>
 #include <9P2000.h>
 #include "../boot/boot.h"
diff --git a/sys/src/kern/boot/bootauth.c b/sys/src/kern/boot/bootauth.c
index 64c3b61..1d357eb 100644
--- a/sys/src/kern/boot/bootauth.c
+++ b/sys/src/kern/boot/bootauth.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <libc.h>
+#include <envvars.h>
 #include <auth.h>
 #include <9P2000.h>
 #include "../boot/boot.h"
@@ -22,7 +23,7 @@ authentication(int cpuflag)
 	char *argv[16], **av;
 	int ac;
 
-	if(jehanne_access(factotumPath, AEXEC) < 0 || jehanne_getenv("user") != nil){
+	if(jehanne_access(factotumPath, AEXEC) < 0 || jehanne_getenv(ENV_USER) != nil){
 		glenda();
 		return;
 	}
@@ -69,7 +70,7 @@ glenda(void)
 	int fd;
 	char *s;
 
-	s = jehanne_getenv("user");
+	s = jehanne_getenv(ENV_USER);
 	if(s == nil)
 		s = "glenda";
 
diff --git a/sys/src/lib/auth/newns.c b/sys/src/lib/auth/newns.c
index 203ba45..f0d7d2f 100644
--- a/sys/src/lib/auth/newns.c
+++ b/sys/src/lib/auth/newns.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <bio.h>
 #include <auth.h>
 #include <authsrv.h>
@@ -65,9 +66,9 @@ buildns(int newns, char *user, char *file)
 	}
 	if(newns){
 		rfork(RFENVG|RFCNAMEG);
-		setenv("user", user);
+		setenv(ENV_USER, user);
 		snprint(home, sizeof home, "/usr/%s", user);
-		setenv("home", home);
+		setenv(ENV_HOME, home);
 	}
 
 	cdroot = nsfile(newns ? "newns" : "addns", b, rpc);
diff --git a/sys/src/lib/authsrv/readnvram.c b/sys/src/lib/authsrv/readnvram.c
index 8beebbb..9d90a37 100644
--- a/sys/src/lib/authsrv/readnvram.c
+++ b/sys/src/lib/authsrv/readnvram.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <authsrv.h>
 
 static int32_t	finddosfile(int, char*);
@@ -137,7 +138,7 @@ findnvram(Nvrwhere *locp)
 	if (nvrfile == nil)
 		nvrfile = getenv("nvram");
 	if (cputype == nil)
-		cputype = getenv("cputype");
+		cputype = getenv(ENV_CPUTYPE);
 	if(cputype == nil)
 		cputype = strdup("mips");
 	if(strcmp(cputype, "386")==0 || strcmp(cputype, "amd64")==0 || strcmp(cputype, "alpha")==0) {
diff --git a/sys/src/lib/disk/proto.c b/sys/src/lib/disk/proto.c
index 90f7faa..509152c 100644
--- a/sys/src/lib/disk/proto.c
+++ b/sys/src/lib/disk/proto.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <bio.h>
 #include <auth.h>
 #include <9P2000.h>
diff --git a/sys/src/lib/draw/newwindow.c b/sys/src/lib/draw/newwindow.c
index b15c557..aa4b69e 100644
--- a/sys/src/lib/draw/newwindow.c
+++ b/sys/src/lib/draw/newwindow.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <draw.h>
 
 /* Connect us to new window, if possible */
@@ -19,7 +20,7 @@ newwindow(char *str)
 	char *wsys;
 	char buf[256];
 
-	wsys = getenv("wsys");
+	wsys = getenv(ENV_WSYS);
 	if(wsys == nil)
 		return -1;
 	fd = open(wsys, ORDWR);
diff --git a/sys/src/lib/draw/scroll.c b/sys/src/lib/draw/scroll.c
index 7253671..a0142ea 100644
--- a/sys/src/lib/draw/scroll.c
+++ b/sys/src/lib/draw/scroll.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <draw.h>
 
 int
diff --git a/sys/src/lib/ndb/ndbopen.c b/sys/src/lib/ndb/ndbopen.c
index c10b22b..a099290 100644
--- a/sys/src/lib/ndb/ndbopen.c
+++ b/sys/src/lib/ndb/ndbopen.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <bio.h>
 #include <ctype.h>
 #include <ndb.h>
diff --git a/sys/src/lib/plumb/mesg.c b/sys/src/lib/plumb/mesg.c
index d3c4284..6be963d 100644
--- a/sys/src/lib/plumb/mesg.c
+++ b/sys/src/lib/plumb/mesg.c
@@ -9,6 +9,7 @@
 
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include "plumb.h"
 
 int
diff --git a/sys/src/lib/posix/environment.c b/sys/src/lib/posix/environment.c
index 7cee478..3d701e9 100644
--- a/sys/src/lib/posix/environment.c
+++ b/sys/src/lib/posix/environment.c
@@ -17,6 +17,7 @@
  */
 #include <u.h>
 #include <lib9.h>
+#include <envvars.h>
 #include <posix.h>
 #include "internal.h"