diff --git a/collects/file/scribblings/md5.scrbl b/collects/file/scribblings/md5.scrbl
index 5fc7dd2b55..2e790e4278 100644
--- a/collects/file/scribblings/md5.scrbl
+++ b/collects/file/scribblings/md5.scrbl
@@ -10,12 +10,15 @@
 
 @defmodule[file/md5]
 
-@defproc[(md5 [in (or/c input-port? bytes? string?)]) bytes?]{
+@defproc[(md5 [in (or/c input-port? bytes? string?)]
+              [hex-encode? boolean? #t]) bytes?]{
 
-Produces a byte string containing 32 hexadecimal digits (lowercase)
+If @racket[hex-encode?] is @racket[#t], produces a byte string containing 32 hexadecimal digits (lowercase)
+that is the MD5 hash of the given input stream or byte string. Otherwise produces the 16 byte long byte string
 that is the MD5 hash of the given input stream or byte string.
 
 @examples[
 #:eval md5-eval
 (md5 #"abc")
+(md5 #"abc" #f)
 ]}