diff --git a/src/exec_monitor.c b/src/exec_monitor.c
index ac113169d..b781fa858 100644
--- a/src/exec_monitor.c
+++ b/src/exec_monitor.c
@@ -97,21 +97,21 @@ deliver_signal(struct monitor_closure *mc, int signo, bool from_parent)
 	break;
     case SIGCONT_FG:
 	/* Continue in foreground, grant it controlling tty. */
-	if (tcsetpgrp(io_fds[SFD_SLAVE], mc->cmnd_pgrp) == -1) {
+	if (tcsetpgrp(io_fds[SFD_FOLLOWER], mc->cmnd_pgrp) == -1) {
 	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO,
 		"%s: unable to set foreground pgrp to %d (command)",
 		__func__, (int)mc->cmnd_pgrp);
 	}
 	/* Lazily initialize the pty if needed. */
 	if (!tty_initialized) {
-	    if (sudo_term_copy(io_fds[SFD_USERTTY], io_fds[SFD_SLAVE]))
+	    if (sudo_term_copy(io_fds[SFD_USERTTY], io_fds[SFD_FOLLOWER]))
 		    tty_initialized = true;
 	}
 	killpg(mc->cmnd_pid, SIGCONT);
 	break;
     case SIGCONT_BG:
 	/* Continue in background, I take controlling tty. */
-	if (tcsetpgrp(io_fds[SFD_SLAVE], mc->mon_pgrp) == -1) {
+	if (tcsetpgrp(io_fds[SFD_FOLLOWER], mc->mon_pgrp) == -1) {
 	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO,
 		"%s: unable to set foreground pgrp to %d (monitor)",
 		__func__, (int)mc->mon_pgrp);
@@ -131,7 +131,7 @@ deliver_signal(struct monitor_closure *mc, int signo, bool from_parent)
 
 /*
  * Unpack rows and cols from a CMD_TTYWINCH value, set the new window
- * size on the pty slave and inform the command of the change.
+ * size on the pty follower and inform the command of the change.
  */
 static void
 handle_winch(struct monitor_closure *mc, unsigned int wsize_packed)
@@ -143,14 +143,14 @@ handle_winch(struct monitor_closure *mc, unsigned int wsize_packed)
     wsize.ws_row = wsize_packed & 0xffff;
     wsize.ws_col = (wsize_packed >> 16) & 0xffff;
 
-    if (ioctl(io_fds[SFD_SLAVE], TIOCGWINSZ, &owsize) == 0 &&
+    if (ioctl(io_fds[SFD_FOLLOWER], TIOCGWINSZ, &owsize) == 0 &&
 	(wsize.ws_row != owsize.ws_row || wsize.ws_col != owsize.ws_col)) {
 
 	sudo_debug_printf(SUDO_DEBUG_INFO,
 	    "window size change %dx%d -> %dx%d",
 	    owsize.ws_col, owsize.ws_row, wsize.ws_col, wsize.ws_row);
 
-	(void)ioctl(io_fds[SFD_SLAVE], TIOCSWINSZ, &wsize);
+	(void)ioctl(io_fds[SFD_FOLLOWER], TIOCSWINSZ, &wsize);
 	deliver_signal(mc, SIGWINCH, true);
     }
 
@@ -242,7 +242,7 @@ mon_handle_sigchld(struct monitor_closure *mc)
 	    mc->cstat->val = status;
 	    if (WIFSTOPPED(status)) {
 		/* Save the foreground pgid so we can restore it later. */
-		pid = tcgetpgrp(io_fds[SFD_SLAVE]);
+		pid = tcgetpgrp(io_fds[SFD_FOLLOWER]);
 		if (pid != mc->mon_pgrp)
 		    mc->cmnd_pgrp = pid;
 		send_status(mc->backchannel, mc->cstat);
@@ -400,15 +400,15 @@ exec_cmnd_pty(struct command_details *details, bool foreground, int errfd)
     /* Wire up standard fds, note that stdout/stderr may be pipes. */
     if (dup3(io_fds[SFD_STDIN], STDIN_FILENO, 0) == -1)
 	sudo_fatal("dup3");
-    if (io_fds[SFD_STDIN] != io_fds[SFD_SLAVE])
+    if (io_fds[SFD_STDIN] != io_fds[SFD_FOLLOWER])
 	close(io_fds[SFD_STDIN]);
     if (dup3(io_fds[SFD_STDOUT], STDOUT_FILENO, 0) == -1)
 	sudo_fatal("dup3");
-    if (io_fds[SFD_STDOUT] != io_fds[SFD_SLAVE])
+    if (io_fds[SFD_STDOUT] != io_fds[SFD_FOLLOWER])
 	close(io_fds[SFD_STDOUT]);
     if (dup3(io_fds[SFD_STDERR], STDERR_FILENO, 0) == -1)
 	sudo_fatal("dup3");
-    if (io_fds[SFD_STDERR] != io_fds[SFD_SLAVE])
+    if (io_fds[SFD_STDERR] != io_fds[SFD_FOLLOWER])
 	close(io_fds[SFD_STDERR]);
 
     /* Wait for parent to grant us the tty if we are foreground. */
@@ -416,15 +416,15 @@ exec_cmnd_pty(struct command_details *details, bool foreground, int errfd)
 	struct timespec ts = { 0, 1000 };  /* 1us */
 	sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: waiting for controlling tty",
 	    __func__);
-	while (tcgetpgrp(io_fds[SFD_SLAVE]) != self)
+	while (tcgetpgrp(io_fds[SFD_FOLLOWER]) != self)
 	    nanosleep(&ts, NULL);
 	sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: got controlling tty",
 	    __func__);
     }
 
-    /* Done with the pty slave, don't leak it. */
-    if (io_fds[SFD_SLAVE] != -1)
-	close(io_fds[SFD_SLAVE]);
+    /* Done with the pty follower, don't leak it. */
+    if (io_fds[SFD_FOLLOWER] != -1)
+	close(io_fds[SFD_FOLLOWER]);
 
     /* Execute command; only returns on error. */
     sudo_debug_printf(SUDO_DEBUG_INFO, "executing %s in the %s",
@@ -551,9 +551,9 @@ exec_monitor(struct command_details *details, sigset_t *oset,
     int errpipe[2];
     debug_decl(exec_monitor, SUDO_DEBUG_EXEC);
 
-    /* The pty master is not used by the monitor. */
-    if (io_fds[SFD_MASTER] != -1)
-	close(io_fds[SFD_MASTER]);
+    /* The pty leader is not used by the monitor. */
+    if (io_fds[SFD_LEADER] != -1)
+	close(io_fds[SFD_LEADER]);
 
     /* Ignore any SIGTTIN or SIGTTOU we receive (shouldn't be possible). */
     memset(&sa, 0, sizeof(sa));
@@ -571,7 +571,7 @@ exec_monitor(struct command_details *details, sigset_t *oset,
 
     /*
      * Start a new session with the parent as the session leader
-     * and the slave pty as the controlling terminal.
+     * and the follower device as the controlling terminal.
      * This allows us to be notified when the command has been suspended.
      */
     if (setsid() == -1) {
@@ -601,7 +601,7 @@ exec_monitor(struct command_details *details, sigset_t *oset,
 #ifdef HAVE_SELINUX
     if (ISSET(details->flags, CD_RBAC_ENABLED)) {
         if (selinux_setup(details->selinux_role, details->selinux_type,
-            details->tty, io_fds[SFD_SLAVE], true) == -1)
+            details->tty, io_fds[SFD_FOLLOWER], true) == -1)
             goto bad;
     }
 #endif
@@ -655,20 +655,20 @@ exec_monitor(struct command_details *details, sigset_t *oset,
     sigprocmask(SIG_SETMASK, oset, NULL);
 
     /* If any of stdin/stdout/stderr are pipes, close them in parent. */
-    if (io_fds[SFD_STDIN] != io_fds[SFD_SLAVE])
+    if (io_fds[SFD_STDIN] != io_fds[SFD_FOLLOWER])
 	close(io_fds[SFD_STDIN]);
-    if (io_fds[SFD_STDOUT] != io_fds[SFD_SLAVE])
+    if (io_fds[SFD_STDOUT] != io_fds[SFD_FOLLOWER])
 	close(io_fds[SFD_STDOUT]);
-    if (io_fds[SFD_STDERR] != io_fds[SFD_SLAVE])
+    if (io_fds[SFD_STDERR] != io_fds[SFD_FOLLOWER])
 	close(io_fds[SFD_STDERR]);
 
     /* Put command in its own process group. */
     mc.cmnd_pgrp = mc.cmnd_pid;
     setpgid(mc.cmnd_pid, mc.cmnd_pgrp);
 
-    /* Make the command the foreground process for the pty slave. */
+    /* Make the command the foreground process for the pty follower. */
     if (foreground && !ISSET(details->flags, CD_EXEC_BG)) {
-	if (tcsetpgrp(io_fds[SFD_SLAVE], mc.cmnd_pgrp) == -1) {
+	if (tcsetpgrp(io_fds[SFD_FOLLOWER], mc.cmnd_pgrp) == -1) {
 	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO,
 		"%s: unable to set foreground pgrp to %d (command)",
 		__func__, (int)mc.cmnd_pgrp);
@@ -700,7 +700,7 @@ exec_monitor(struct command_details *details, sigset_t *oset,
      * Take the controlling tty.  This prevents processes spawned by the
      * command from receiving SIGHUP when the session leader (us) exits.
      */
-    if (tcsetpgrp(io_fds[SFD_SLAVE], mc.mon_pgrp) == -1) {
+    if (tcsetpgrp(io_fds[SFD_FOLLOWER], mc.mon_pgrp) == -1) {
 	sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO,
 	    "%s: unable to set foreground pgrp to %d (monitor)",
 	    __func__, (int)mc.mon_pgrp);
diff --git a/src/exec_pty.c b/src/exec_pty.c
index 1880893a4..97a283c58 100644
--- a/src/exec_pty.c
+++ b/src/exec_pty.c
@@ -132,7 +132,7 @@ pty_cleanup(void)
 
 /*
  * Allocate a pty if /dev/tty is a tty.
- * Fills in io_fds[SFD_USERTTY], io_fds[SFD_MASTER], io_fds[SFD_SLAVE]
+ * Fills in io_fds[SFD_USERTTY], io_fds[SFD_LEADER], io_fds[SFD_FOLLOWER]
  * and ptyname globals.
  */
 static bool
@@ -147,7 +147,7 @@ pty_setup(struct command_details *details, const char *tty)
 	debug_return_bool(false);
     }
 
-    if (!get_pty(&io_fds[SFD_MASTER], &io_fds[SFD_SLAVE],
+    if (!get_pty(&io_fds[SFD_LEADER], &io_fds[SFD_FOLLOWER],
 	ptyname, sizeof(ptyname), details->euid))
 	sudo_fatal(U_("unable to allocate pty"));
 
@@ -158,30 +158,30 @@ pty_setup(struct command_details *details, const char *tty)
     if (ISSET(details->flags, CD_SET_UTMP)) {
 	utmp_user =
 	    details->utmp_user ? details->utmp_user : user_details.username;
-	utmp_login(tty, ptyname, io_fds[SFD_SLAVE], utmp_user);
+	utmp_login(tty, ptyname, io_fds[SFD_FOLLOWER], utmp_user);
     }
 
     sudo_debug_printf(SUDO_DEBUG_INFO,
-	"%s: %s fd %d, pty master fd %d, pty slave fd %d",
-	__func__, _PATH_TTY, io_fds[SFD_USERTTY], io_fds[SFD_MASTER],
-	io_fds[SFD_SLAVE]);
+	"%s: %s fd %d, pty leader fd %d, pty follower fd %d",
+	__func__, _PATH_TTY, io_fds[SFD_USERTTY], io_fds[SFD_LEADER],
+	io_fds[SFD_FOLLOWER]);
 
     debug_return_bool(true);
 }
 
 /*
- * Make the tty slave the controlling tty.
+ * Make the tty follower the controlling tty.
  * This is only used by the monitor but ptyname[] is static.
  */
 int
 pty_make_controlling(void)
 {
-    if (io_fds[SFD_SLAVE] != -1) {
+    if (io_fds[SFD_FOLLOWER] != -1) {
 #ifdef TIOCSCTTY
-	if (ioctl(io_fds[SFD_SLAVE], TIOCSCTTY, NULL) != 0)
+	if (ioctl(io_fds[SFD_FOLLOWER], TIOCSCTTY, NULL) != 0)
 	    return -1;
 #else
-	/* Set controlling tty by reopening pty slave. */
+	/* Set controlling tty by reopening pty follower. */
 	int fd = open(ptyname, O_RDWR);
 	if (fd == -1)
 	    return -1;
@@ -840,7 +840,7 @@ io_buf_new(int rfd, int wfd,
 }
 
 /*
- * We already closed the slave pty so reads from the master will not block.
+ * We already closed the follower so reads from the leader will not block.
  */
 static void
 pty_finish(struct command_status *cstat)
@@ -1424,19 +1424,19 @@ exec_pty(struct command_details *details, struct command_status *cstat)
      * In background mode there is no stdin.
      */
     if (!ISSET(details->flags, CD_BACKGROUND))
-	io_fds[SFD_STDIN] = io_fds[SFD_SLAVE];
-    io_fds[SFD_STDOUT] = io_fds[SFD_SLAVE];
-    io_fds[SFD_STDERR] = io_fds[SFD_SLAVE];
+	io_fds[SFD_STDIN] = io_fds[SFD_FOLLOWER];
+    io_fds[SFD_STDOUT] = io_fds[SFD_FOLLOWER];
+    io_fds[SFD_STDERR] = io_fds[SFD_FOLLOWER];
 
     if (io_fds[SFD_USERTTY] != -1) {
-	/* Read from /dev/tty, write to pty master */
+	/* Read from /dev/tty, write to pty leader */
 	if (!ISSET(details->flags, CD_BACKGROUND)) {
-	    io_buf_new(io_fds[SFD_USERTTY], io_fds[SFD_MASTER],
+	    io_buf_new(io_fds[SFD_USERTTY], io_fds[SFD_LEADER],
 		log_ttyin, &ec, &iobufs);
 	}
 
-	/* Read from pty master, write to /dev/tty */
-	io_buf_new(io_fds[SFD_MASTER], io_fds[SFD_USERTTY],
+	/* Read from pty leader, write to /dev/tty */
+	io_buf_new(io_fds[SFD_LEADER], io_fds[SFD_USERTTY],
 	    log_ttyout, &ec, &iobufs);
 
 	/* Are we the foreground process? */
@@ -1511,8 +1511,8 @@ exec_pty(struct command_details *details, struct command_status *cstat)
     }
 
     if (foreground) {
-	/* Copy terminal attrs from user tty -> pty slave. */
-	if (!sudo_term_copy(io_fds[SFD_USERTTY], io_fds[SFD_SLAVE])) {
+	/* Copy terminal attrs from user tty -> pty follower. */
+	if (!sudo_term_copy(io_fds[SFD_USERTTY], io_fds[SFD_FOLLOWER])) {
             sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO,
                 "%s: unable to copy terminal settings to pty", __func__);
 	    foreground = false;
@@ -1570,16 +1570,16 @@ exec_pty(struct command_details *details, struct command_status *cstat)
     }
 
     /*
-     * We close the pty slave so only the monitor and command have a
+     * We close the pty follower so only the monitor and command have a
      * reference to it.  This ensures that we can don't block reading
-     * from the master when the command and monitor have exited.
+     * from the leader when the command and monitor have exited.
      */
-    if (io_fds[SFD_SLAVE] != -1) {
-	close(io_fds[SFD_SLAVE]);
-	io_fds[SFD_SLAVE] = -1;
+    if (io_fds[SFD_FOLLOWER] != -1) {
+	close(io_fds[SFD_FOLLOWER]);
+	io_fds[SFD_FOLLOWER] = -1;
     }
 
-    /* Tell the monitor to continue now that the slave is closed. */
+    /* Tell the monitor to continue now that the follower is closed. */
     cstat->type = CMD_SIGNO;
     cstat->val = 0;
     while (send(sv[0], cstat, sizeof(*cstat), 0) == -1) {
@@ -1622,8 +1622,8 @@ exec_pty(struct command_details *details, struct command_status *cstat)
     setlocale(LC_ALL, "C");
 
     /*
-     * In the event loop we pass input from user tty to master
-     * and pass output from master to stdout and IO plugin.
+     * In the event loop we pass input from user tty to leader
+     * and pass output from leader to stdout and IO plugin.
      * Try to recover on ENXIO, it means the tty was revoked.
      */
     add_io_events(ec.evbase);
diff --git a/src/get_pty.c b/src/get_pty.c
index 75c5374d2..e50a9a633 100644
--- a/src/get_pty.c
+++ b/src/get_pty.c
@@ -52,7 +52,7 @@
 
 #if defined(HAVE_OPENPTY)
 bool
-get_pty(int *master, int *slave, char *name, size_t namesz, uid_t ttyuid)
+get_pty(int *leader, int *follower, char *name, size_t namesz, uid_t ttyuid)
 {
     struct group *gr;
     gid_t ttygid = -1;
@@ -62,7 +62,7 @@ get_pty(int *master, int *slave, char *name, size_t namesz, uid_t ttyuid)
     if ((gr = getgrnam("tty")) != NULL)
 	ttygid = gr->gr_gid;
 
-    if (openpty(master, slave, name, NULL, NULL) == 0) {
+    if (openpty(leader, follower, name, NULL, NULL) == 0) {
 	if (chown(name, ttyuid, ttygid) == 0)
 	    ret = true;
     }
@@ -72,23 +72,23 @@ get_pty(int *master, int *slave, char *name, size_t namesz, uid_t ttyuid)
 
 #elif defined(HAVE__GETPTY)
 bool
-get_pty(int *master, int *slave, char *name, size_t namesz, uid_t ttyuid)
+get_pty(int *leader, int *follower, char *name, size_t namesz, uid_t ttyuid)
 {
     char *line;
     bool ret = false;
     debug_decl(get_pty, SUDO_DEBUG_PTY);
 
     /* IRIX-style dynamic ptys (may fork) */
-    line = _getpty(master, O_RDWR, S_IRUSR|S_IWUSR|S_IWGRP, 0);
+    line = _getpty(leader, O_RDWR, S_IRUSR|S_IWUSR|S_IWGRP, 0);
     if (line != NULL) {
-	*slave = open(line, O_RDWR|O_NOCTTY, 0);
-	if (*slave != -1) {
+	*follower = open(line, O_RDWR|O_NOCTTY, 0);
+	if (*follower != -1) {
 	    (void) chown(line, ttyuid, -1);
 	    strlcpy(name, line, namesz);
 	    ret = true;
 	} else {
-	    close(*master);
-	    *master = -1;
+	    close(*leader);
+	    *leader = -1;
 	}
     }
     debug_return_bool(ret);
@@ -110,32 +110,32 @@ posix_openpt(int oflag)
 # endif /* HAVE_POSIX_OPENPT */
 
 bool
-get_pty(int *master, int *slave, char *name, size_t namesz, uid_t ttyuid)
+get_pty(int *leader, int *follower, char *name, size_t namesz, uid_t ttyuid)
 {
     char *line;
     bool ret = false;
     debug_decl(get_pty, SUDO_DEBUG_PTY);
 
-    *master = posix_openpt(O_RDWR|O_NOCTTY);
-    if (*master != -1) {
-	(void) grantpt(*master); /* may fork */
-	if (unlockpt(*master) != 0) {
-	    close(*master);
+    *leader = posix_openpt(O_RDWR|O_NOCTTY);
+    if (*leader != -1) {
+	(void) grantpt(*leader); /* may fork */
+	if (unlockpt(*leader) != 0) {
+	    close(*leader);
 	    goto done;
 	}
-	line = ptsname(*master);
+	line = ptsname(*leader);
 	if (line == NULL) {
-	    close(*master);
+	    close(*leader);
 	    goto done;
 	}
-	*slave = open(line, O_RDWR|O_NOCTTY, 0);
-	if (*slave == -1) {
-	    close(*master);
+	*follower = open(line, O_RDWR|O_NOCTTY, 0);
+	if (*follower == -1) {
+	    close(*leader);
 	    goto done;
 	}
 # if defined(I_PUSH) && !defined(_AIX)
-	ioctl(*slave, I_PUSH, "ptem");	/* pseudo tty emulation module */
-	ioctl(*slave, I_PUSH, "ldterm");	/* line discipline module */
+	ioctl(*follower, I_PUSH, "ptem");	/* pseudo tty emulation module */
+	ioctl(*follower, I_PUSH, "ldterm");	/* line discipline module */
 # endif
 	(void) chown(line, ttyuid, -1);
 	strlcpy(name, line, namesz);
@@ -150,7 +150,7 @@ done:
 static char line[] = _PATH_DEV "ptyXX";
 
 bool
-get_pty(int *master, int *slave, char *name, size_t namesz, uid_t ttyuid)
+get_pty(int *leader, int *follower, char *name, size_t namesz, uid_t ttyuid)
 {
     char *bank, *cp;
     struct group *gr;
@@ -165,8 +165,8 @@ get_pty(int *master, int *slave, char *name, size_t namesz, uid_t ttyuid)
 	line[sizeof(_PATH_DEV "ptyX") - 2] = *bank;
 	for (cp = "0123456789abcdef"; *cp != '\0'; cp++) {
 	    line[sizeof(_PATH_DEV "ptyXX") - 2] = *cp;
-	    *master = open(line, O_RDWR|O_NOCTTY, 0);
-	    if (*master == -1) {
+	    *leader = open(line, O_RDWR|O_NOCTTY, 0);
+	    if (*leader == -1) {
 		if (errno == ENOENT)
 		    goto done; /* out of ptys */
 		continue; /* already in use */
@@ -177,13 +177,13 @@ get_pty(int *master, int *slave, char *name, size_t namesz, uid_t ttyuid)
 # ifdef HAVE_REVOKE
 	    (void) revoke(line);
 # endif
-	    *slave = open(line, O_RDWR|O_NOCTTY, 0);
-	    if (*slave != -1) {
+	    *follower = open(line, O_RDWR|O_NOCTTY, 0);
+	    if (*follower != -1) {
 		    strlcpy(name, line, namesz);
 		    ret = true; /* success */
 		    goto done;
 	    }
-	    (void) close(*master);
+	    (void) close(*leader);
 	}
     }
 done:
diff --git a/src/sudo.h b/src/sudo.h
index da005c831..2a3c5050f 100644
--- a/src/sudo.h
+++ b/src/sudo.h
@@ -213,7 +213,7 @@ int parse_args(int argc, char **argv, int *old_optind, int *nargc,
 extern int tgetpass_flags;
 
 /* get_pty.c */
-bool get_pty(int *master, int *slave, char *name, size_t namesz, uid_t uid);
+bool get_pty(int *leader, int *follower, char *name, size_t namesz, uid_t uid);
 
 /* sudo.c */
 int policy_init_session(struct command_details *details);
diff --git a/src/sudo_exec.h b/src/sudo_exec.h
index 000a55c34..39164a785 100644
--- a/src/sudo_exec.h
+++ b/src/sudo_exec.h
@@ -41,8 +41,8 @@
 #define SFD_STDIN	0
 #define SFD_STDOUT	1
 #define SFD_STDERR	2
-#define SFD_MASTER	3
-#define SFD_SLAVE	4
+#define SFD_LEADER	3
+#define SFD_FOLLOWER	4
 #define SFD_USERTTY	5
 
 /*