diff --git a/collects/readline/doc.txt b/collects/readline/doc.txt
index 9da65d1d56..5a37dc5a01 100644
--- a/collects/readline/doc.txt
+++ b/collects/readline/doc.txt
@@ -10,8 +10,8 @@ Normal use of readline
 The _rep.ss_ library installs a readline-based function for the
 prompt-and-read part of MzScheme's read-eval-print loop.
 
-You can put the following in your ~/.mzschemerc so that MzScheme starts with
-readline support on xterms:
+You can put the following in your ~/.mzschemerc so that MzScheme
+starts with readline support on xterms:
 
   (when (equal? "xterm" (getenv "TERM"))
     (dynamic-require '(lib "rep.ss" "readline") #f))
@@ -28,11 +28,20 @@ The _readline.ss_ library provides two functions:
 > (readline prompt-string)
   prints the given prompt string and reads a line
 
+> (readline-bytes prompt-bytes)
+  same as above, but using raw byte-strings for the prompt and
+  returning a byte string
+
 > (add-history s)
   adds the given string to the readline history, which is accessible
   to the user via the up-arrow key
 
-> (set-completion-function! proc)
+> (add-history-bytes s)
+  adds the given byte string to the readline history, which is
+  accessible to the user via the up-arrow key
+
+> (set-completion-function! proc [type])
   sets readline's `rl_completion_entry_function' function according to
   proc, which is expected to be a `string -> (list-of string)'
-  procedure
+  procedure; the `type' argument defaults to `_string' but you can use
+  it with `_bytes' instead
diff --git a/collects/readline/mzrl.ss b/collects/readline/mzrl.ss
index 254bedd83e..3db3f93c8c 100644
--- a/collects/readline/mzrl.ss
+++ b/collects/readline/mzrl.ss
@@ -1,7 +1,9 @@
 (module mzrl mzscheme
 
 (require (lib "foreign.ss")) (unsafe!)
-(provide readline add-history set-completion-function!)
+(provide readline readline-bytes
+         add-history add-history-bytes
+         set-completion-function!)
 
 ;; libtermcap maybe needed
 (define libtermcap  (with-handlers ([exn:fail? void]) (ffi-lib "libtermcap")))
@@ -10,17 +12,26 @@
 (define readline
   (get-ffi-obj "readline" libreadline (_fun _string -> _string/eof)))
 
+(define readline-bytes
+  (get-ffi-obj "readline" libreadline (_fun _bytes -> _bytes/eof)))
+
 (define add-history
   (get-ffi-obj "add_history" libreadline (_fun _string -> _void)))
 
+(define add-history-bytes
+  (get-ffi-obj "add_history" libreadline (_fun _bytes -> _void)))
+
 ;; Simple completion: use this with a (string -> list-of string) function that
 ;; returns the completions for a given string.  (should clean up bytes/string)
-(define (set-completion-function! func)
-  (if func
-    (set-ffi-obj! "rl_completion_entry_function" libreadline
-                  (_fun _string _int -> _pointer)
-                  (completion-function func))
-    (set-ffi-obj! "rl_completion_entry_function" libreadline _pointer #f)))
+(define set-completion-function!
+  (case-lambda
+    [(func) (set-completion-function! _string)]
+    [(func type)
+     (if func
+       (set-ffi-obj! "rl_completion_entry_function" libreadline
+                     (_fun type _int -> _pointer)
+                     (completion-function func))
+       (set-ffi-obj! "rl_completion_entry_function" libreadline _pointer #f))]))
 (define (completion-function func)
   (let ([cur '()])
     (define (complete str state)
@@ -31,10 +42,16 @@
                (set! cur (cdr cur))))))
     complete))
 
-(set-ffi-obj! "rl_readline_name" libreadline _string "mzscheme")
+(set-ffi-obj! "rl_readline_name" libreadline _bytes #"mzscheme")
+
+;; need to capture the real input port below
+(define real-input-port (current-input-port))
+(unless (eq? 'stdin (object-name (current-input-port)))
+  (fprintf (current-output-port)
+           "mzrl warning: could not capture the real input port"))
 
 ;; make it possible to run Scheme threads while waiting for input
 (set-ffi-obj! "rl_event_hook" libreadline (_fun -> _int)
-              (lambda () (sync/enable-break (current-input-port)) 0))
+              (lambda () (sync/enable-break real-input-port) 0))
 
 )
diff --git a/collects/readline/readline.ss b/collects/readline/readline.ss
index 8dcdd50127..54e6677bc9 100644
--- a/collects/readline/readline.ss
+++ b/collects/readline/readline.ss
@@ -1,4 +1,4 @@
 
 (module readline mzscheme
   (require "mzrl.ss")
-  (provide readline add-history set-completion-function!))
+  (provide (all-from "mzrl.ss")))