diff --git a/collects/scribblings/gui/clipboard-client-class.scrbl b/collects/scribblings/gui/clipboard-client-class.scrbl
index 8e256408..3ad8deab 100644
--- a/collects/scribblings/gui/clipboard-client-class.scrbl
+++ b/collects/scribblings/gui/clipboard-client-class.scrbl
@@ -18,7 +18,7 @@ Creates a clipboard client that supports no data formats.
 
 }
 
-@defmethod[(add-type [format string])
+@defmethod[(add-type [format string?])
            void?]{
 
 Adds a new data format name to the list supported by the clipboard
@@ -28,7 +28,7 @@ Adds a new data format name to the list supported by the clipboard
 
 }
 
-@defmethod[(get-data [format string])
+@defmethod[(get-data [format string?])
            (or/c bytes? string? false/c)]{
 
 Called when a process requests clipboard data while this client is the
diff --git a/collects/scribblings/gui/clipboard-intf.scrbl b/collects/scribblings/gui/clipboard-intf.scrbl
index 975504b6..bb1807c6 100644
--- a/collects/scribblings/gui/clipboard-intf.scrbl
+++ b/collects/scribblings/gui/clipboard-intf.scrbl
@@ -45,7 +45,7 @@ See @|timediscuss| for a discussion of the @scheme[time] argument.  If
 
 @defmethod[(get-clipboard-data [format string]
                                [time (and/c exact? integer?)])
-           (or/c byte string false/c)]{
+           (or/c bytes? string? false/c)]{
 
 Gets the current clipboard contents in a specific format, returning
  @scheme[#f] if the clipboard does not contain data in the requested