diff --git a/collects/mrlib/gif.ss b/collects/mrlib/gif.ss
index 215255b5..7c6f323e 100644
--- a/collects/mrlib/gif.ss
+++ b/collects/mrlib/gif.ss
@@ -17,7 +17,7 @@
         (cons (subbytes b offset (+ offset len))
               (split-bytes b len (+ offset len)))))
   
-  (define (write-gifs bms delay filename one-at-a-time? last-frame-delay)
+  (define (write-gifs bms delay filename one-at-a-time? last-frame-delay loop?)
     (let* ([init (force-bm (car bms))]
            [w (send init get-width)]
            [h (send init get-height)])
@@ -38,7 +38,7 @@
              filename
              (lambda (p)
                (let* ([gif (gif-start p w h 0 #f)])
-                 (when delay
+                 (when loop?
                    (gif-add-loop-control gif 0))
                  (let ([last-argb-thunk (last argb-thunks)])
                    (for-each (lambda (argb-thunk)
@@ -74,11 +74,12 @@
                    (gif-end gif)))))))))
   
   (define (write-gif bm filename)
-    (write-gifs (list bm) #f filename #f #f))
+    (write-gifs (list bm) #f filename #f #f #f))
   
   (define (write-animated-gif bms delay filename 
                               #:one-at-a-time? [one-at-a-time? #f]
-                              #:last-frame-delay [last-frame-delay #f])
-    (write-gifs bms delay filename one-at-a-time? last-frame-delay))
+                              #:last-frame-delay [last-frame-delay #f]
+                              #:loop? [loop? (and delay #t)])
+    (write-gifs bms delay filename one-at-a-time? last-frame-delay loop?))
   
   )
diff --git a/collects/mrlib/scribblings/gif.scrbl b/collects/mrlib/scribblings/gif.scrbl
index db5ed168..0b4916ed 100644
--- a/collects/mrlib/scribblings/gif.scrbl
+++ b/collects/mrlib/scribblings/gif.scrbl
@@ -25,31 +25,34 @@ transparent pixels in the generated GIF image.}
                                                     (-> (is-a?/c bitmap%))))]
                              [delay-csec (integer-in 0 #xFFFFFFFF)]
                              [filename path-string]
+                             [#:loop loop? any/c (and delay-csec #t)]
                              [#:one-at-a-time? one-at-a-time? any/c #f]
                              [#:last-frame-delay last-frame-delay (or/c (integer-in 0 #xFFFFFFFF) false/c) #f])
          void?]{
 
-Writes the bitmaps in @scheme[bitmap-list] to @scheme[filename] as an
-animated GIF. The @scheme[bitmap-list] list can contain a mixture of
+Writes the bitmaps in @scheme[bitmaps] to @scheme[filename] as an
+animated GIF. The @scheme[bitmaps] list can contain a mixture of
 @scheme[bitmap%] objects and thunks (each called just once) that
 produce @scheme[bitmap%] objects. The @scheme[delay-csec] argument is
 the amount of time in 1/100s of a second to wait between transitions.
+If @scheme[loop?] is a true value, then the GIF is marked as a looping
+animation.
 
 If @scheme[one-at-a-time?] is @scheme[#f], then the content of all
 images is collected and quantized at once, to produce a single
 colortable; a drawback to this approach is that it uses more memory,
 and it allows less color variation among animation frames. Even when
 @scheme[one-at-a-time?] is @scheme[#f], the result of each thunk in
-@scheme[bitmap-list] is converted to a byte-string one at a time
+@scheme[bitmaps] is converted to a byte-string one at a time
 (which helps avoid bitmap-count limits under Windows).
 
 If @scheme[one-at-a-time?] is true, then the bitmaps are quantized and
 written to the file one at a time; that is, for each thunk in
-@scheme[bitmap-list], its result is written and discarded before
-another thunk is called. A drawback to this approach is that a
-separate colortable is written for each frame in the animation, which
-can make the resulting file large.
+@scheme[bitmaps], its result is written and discarded before another
+thunk is called. A drawback to this approach is that a separate
+colortable is written for each frame in the animation, which can make
+the resulting file large.
 
 If @scheme[last-frame-delay] is not false, a delay of
-@scheme[last-frame-delay] (in 1/100s of a second) will be added to the
-last frame.}
\ No newline at end of file
+@scheme[last-frame-delay] (in 1/100s of a second) is added to the last
+frame. This extra delay is useful when @scheme[loop?] is true.}