diff --git a/collects/scribblings/reference/bytes.scrbl b/collects/scribblings/reference/bytes.scrbl
index f3d9465309..439c21cc3f 100644
--- a/collects/scribblings/reference/bytes.scrbl
+++ b/collects/scribblings/reference/bytes.scrbl
@@ -90,13 +90,13 @@ positions are initialized with the given @scheme[b]s.
 
 
 @defproc[(subbytes [bstr bytes?] [start exact-nonnegative-integer?]
- [end exact-nonnegative-integer? (bytes-length str)]) bytes?]{
- Returns a new mutable byte string that is @scheme[(- end start)]
- bytes long, and that contains the same bytes
- as @scheme[bstr] from @scheme[start] inclusive to @scheme[end] exclusive.  The
- @scheme[start] and @scheme[end] arguments must be less than the length of
- @scheme[bstr], and @scheme[end] must be greater than or equal to @scheme[start],
- otherwise the @exnraise[exn:fail:contract].
+ [end exact-nonnegative-integer? (bytes-length str)]) bytes?]{ Returns
+ a new mutable byte string that is @scheme[(- end start)] bytes long,
+ and that contains the same bytes as @scheme[bstr] from @scheme[start]
+ inclusive to @scheme[end] exclusive.  The @scheme[start] and
+ @scheme[end] arguments must be less than or equal to the length of
+ @scheme[bstr], and @scheme[end] must be greater than or equal to
+ @scheme[start], otherwise the @exnraise[exn:fail:contract].
 
 @mz-examples[(subbytes #"Apple" 1 3)
              (subbytes #"Apple" 1)]}
diff --git a/collects/scribblings/reference/strings.scrbl b/collects/scribblings/reference/strings.scrbl
index de46ec1daf..020caddb3c 100644
--- a/collects/scribblings/reference/strings.scrbl
+++ b/collects/scribblings/reference/strings.scrbl
@@ -85,11 +85,12 @@ Returns an immutable string with the same content as
 @defproc[(substring [str string?] [start exact-nonnegative-integer?]
  [end exact-nonnegative-integer? (string-length str)]) string?]{
  Returns a new mutable string that is @scheme[(- end start)]
- characters long, and that contains the same characters
- as @scheme[str] from @scheme[start] inclusive to @scheme[end] exclusive.  The
- @scheme[start] and @scheme[end] arguments must be less than the length of
- @scheme[str], and @scheme[end] must be greater than or equal to @scheme[start],
- otherwise the @exnraise[exn:fail:contract].
+ characters long, and that contains the same characters as
+ @scheme[str] from @scheme[start] inclusive to @scheme[end] exclusive.
+ The @scheme[start] and @scheme[end] arguments must be less than or
+ equal to the length of @scheme[str], and @scheme[end] must be greater
+ than or equal to @scheme[start], otherwise the
+ @exnraise[exn:fail:contract].
 
 @mz-examples[(substring "Apple" 1 3)
              (substring "Apple" 1)]}