diff --git a/scsh/pty.scm b/scsh/pty.scm
index f974fb4..1f8b3da 100644
--- a/scsh/pty.scm
+++ b/scsh/pty.scm
@@ -21,8 +21,7 @@
     (let* ((process (fork (lambda ()
 			    (close-input-port pty-in)
 			    (become-session-leader)
-			    (let ((tty (open-control-tty ttyname
-							 open/read+write)))
+			    (let ((tty (open-control-tty ttyname)))
 			      (move->fdes   tty 0)
 			      (dup->outport tty 1)
 			      (set-port-buffering (dup->outport tty 2)
diff --git a/scsh/tty.scm b/scsh/tty.scm
index b4d8a0b..6558ca1 100644
--- a/scsh/tty.scm
+++ b/scsh/tty.scm
@@ -318,7 +318,7 @@
 ;;; This limted functionality is about all we can provide portably across BSD,
 ;;; SunOS, and SVR4.
 
-(define (open-control-tty ttyname maybe-flags)
+(define (open-control-tty ttyname . maybe-flags)
   (let ((flags (optional-arg maybe-flags open/read+write)))
     (receive (errno fd) (open-control-tty/errno ttyname flags)
       (if errno