diff --git a/collects/scribblings/reference/sequences.scrbl b/collects/scribblings/reference/sequences.scrbl
index 80315d5a02..8a66923493 100644
--- a/collects/scribblings/reference/sequences.scrbl
+++ b/collects/scribblings/reference/sequences.scrbl
@@ -193,7 +193,7 @@ its value from @scheme[hash] (as opposed to using @scheme[hash] directly
 as a sequence to get the key and value as separate values for each
 element).}
 
-@defproc[(in-directory [dir (or/c #f path-string?)]) sequence?]{
+@defproc[(in-directory [dir (or/c #f path-string?) #f]) sequence?]{
 
 Return a sequence that produces all of the paths for files,
 directories, and links with @racket[dir]. If @racket[dir] is not