diff --git a/sys/src/9/port/chan.c b/sys/src/9/port/chan.c
index 82529ff3e..373c3b4cb 100644
--- a/sys/src/9/port/chan.c
+++ b/sys/src/9/port/chan.c
@@ -1399,8 +1399,6 @@ namec(char *aname, int amode, int omode, ulong perm)
 		 */
 		n = chartorune(&r, up->genbuf+1)+1;
 		/* actually / is caught by parsing earlier */
-		if(utfrune("M", r) != nil)
-			error(Enoattach);
 		if(up->pgrp->noattach && utfrune("|decp", r)==nil)
 			error(Enoattach);
 		t = devno(r, 1);
diff --git a/sys/src/9/port/devmnt.c b/sys/src/9/port/devmnt.c
index 9f6728a4b..65bdf5453 100644
--- a/sys/src/9/port/devmnt.c
+++ b/sys/src/9/port/devmnt.c
@@ -302,21 +302,11 @@ mntauth(Chan *c, char *spec)
 
 }
 
-static Chan*
-mntattach(char *muxattach)
+Chan*
+mntattach(Chan *c, Chan *ac, char *spec, int flags)
 {
 	Mnt *m;
-	Chan *c;
 	Mntrpc *r;
-	struct bogus{
-		Chan	*chan;
-		Chan	*authchan;
-		char	*spec;
-		int	flags;
-	}bogus;
-
-	bogus = *((struct bogus *)muxattach);
-	c = bogus.chan;
 
 	m = c->mux;
 	if(m == nil){
@@ -342,12 +332,12 @@ mntattach(char *muxattach)
 	}
 	r->request.type = Tattach;
 	r->request.fid = c->fid;
-	if(bogus.authchan == nil)
+	if(ac == nil)
 		r->request.afid = NOFID;
 	else
-		r->request.afid = bogus.authchan->fid;
+		r->request.afid = ac->fid;
 	r->request.uname = up->user;
-	r->request.aname = bogus.spec;
+	r->request.aname = spec;
 	mountrpc(m, r);
 
 	c->qid = r->reply.qid;
@@ -360,11 +350,18 @@ mntattach(char *muxattach)
 
 	poperror();	/* c */
 
-	if(bogus.flags&MCACHE)
+	if(flags&MCACHE)
 		c->flag |= CCACHE;
 	return c;
 }
 
+static Chan*
+noattach(char *)
+{
+	error(Enoattach);
+	return nil;
+}
+
 static Chan*
 mntchan(void)
 {
@@ -1422,7 +1419,7 @@ Dev mntdevtab = {
 	mntreset,
 	devinit,
 	devshutdown,
-	mntattach,
+	noattach,
 	mntwalk,
 	mntstat,
 	mntopen,
diff --git a/sys/src/9/port/devshr.c b/sys/src/9/port/devshr.c
index e959261cb..03a79bc8a 100644
--- a/sys/src/9/port/devshr.c
+++ b/sys/src/9/port/devshr.c
@@ -724,12 +724,6 @@ shrwrite(Chan *c, void *va, long n, vlong)
 	Chan *bc, *c0;
 	Mhead *h;
 	Mount *m;
-	struct{
-		Chan	*chan;
-		Chan	*authchan;
-		char	*spec;
-		int	flags;
-	}bogus;
 
 	if(up->pgrp->noattach)
 		error(Enoattach);
@@ -758,11 +752,7 @@ shrwrite(Chan *c, void *va, long n, vlong)
 		cclose(bc);
 		nexterror();
 	}
-	bogus.flags = 0;
-	bogus.chan = bc;
-	bogus.authchan = nil;
-	bogus.spec = aname;
-	c0 = devtab[devno('M', 0)]->attach((char*)&bogus);
+	c0 = mntattach(bc, nil, aname, 0);
 	poperror();
 	cclose(bc);
 	poperror();
diff --git a/sys/src/9/port/portfns.h b/sys/src/9/port/portfns.h
index db547d1a1..15ca191a3 100644
--- a/sys/src/9/port/portfns.h
+++ b/sys/src/9/port/portfns.h
@@ -173,6 +173,7 @@ uvlong		mk64fract(uvlong, uvlong);
 void		mkqid(Qid*, vlong, ulong, int);
 void		mmurelease(Proc*);
 void		mmuswitch(Proc*);
+Chan*		mntattach(Chan*, Chan*, char*, int);
 Chan*		mntauth(Chan*, char*);
 long		mntversion(Chan*, char*, int, int);
 void		mouseresize(void);
diff --git a/sys/src/9/port/sysfile.c b/sys/src/9/port/sysfile.c
index 43d384c2e..0b0e2e94c 100644
--- a/sys/src/9/port/sysfile.c
+++ b/sys/src/9/port/sysfile.c
@@ -1006,12 +1006,6 @@ bindmount(int ismount, int fd, int afd, char* arg0, char* arg1, ulong flag, char
 {
 	int ret;
 	Chan *c0, *c1, *ac, *bc;
-	struct{
-		Chan	*chan;
-		Chan	*authchan;
-		char	*spec;
-		int	flags;
-	}bogus;
 
 	if((flag&~MMASK) || (flag&MORDER)==(MBEFORE|MAFTER))
 		error(Ebadarg);
@@ -1039,12 +1033,7 @@ bindmount(int ismount, int fd, int afd, char* arg0, char* arg1, ulong flag, char
 		if(afd >= 0)
 			ac = fdtochan(afd, ORDWR, 0, 1);
 
-		bogus.flags = flag & MCACHE;
-		bogus.chan = bc;
-		bogus.authchan = ac;
-		bogus.spec = spec;
-		ret = devno('M', 0);
-		c0 = devtab[ret]->attach((char*)&bogus);
+		c0 = mntattach(bc, ac, spec, flag&MCACHE);
 		poperror();	/* ac bc */
 		if(ac != nil)
 			cclose(ac);