diff --git a/pkgs/redex-pkgs/redex-doc/redex/scribblings/ref.scrbl b/pkgs/redex-pkgs/redex-doc/redex/scribblings/ref.scrbl
index 4e9efdebe2..be6275c981 100644
--- a/pkgs/redex-pkgs/redex-doc/redex/scribblings/ref.scrbl
+++ b/pkgs/redex-pkgs/redex-doc/redex/scribblings/ref.scrbl
@@ -2371,8 +2371,8 @@ exploring reduction sequences.
                  [#:racket-colors? racket-colors? boolean? #t]
                  [#:scheme-colors? scheme-colors? boolean? racket-colors?]
                  [#:filter term-filter (-> any/c (or/c #f string?) any/c) (λ (x y) #t)]
-                 [#:x-spacing x-spacing number? 15]
-                 [#:y-spacing y-spacing number? 15]
+                 [#:x-spacing x-spacing real? 15]
+                 [#:y-spacing y-spacing real? 15]
                  [#:layout layout (-> (listof term-node?) void?) void]
                  [#:edge-labels? edge-labels? boolean? #t]
                  [#:edge-label-font edge-label-font (or/c #f (is-a?/c font%)) #f]
@@ -2454,7 +2454,7 @@ The @racket[term-filter] function is called each time a new node is
 about to be inserted into the graph. If the filter returns false, the
 node is not inserted into the graph.
 
-The @racket[x-spacing] and @racket[y-spacing] control the amount of
+The @racket[x-spacing] and @racket[y-spacing] arguments control the amount of
 space put between the snips in the default layout.
 
 The @racket[layout] argument is called (with all of the terms) when
diff --git a/pkgs/redex-pkgs/redex-gui-lib/redex/gui.rkt b/pkgs/redex-pkgs/redex-gui-lib/redex/gui.rkt
index 6d03e1eb78..49e1d2baad 100644
--- a/pkgs/redex-pkgs/redex-gui-lib/redex/gui.rkt
+++ b/pkgs/redex-pkgs/redex-gui-lib/redex/gui.rkt
@@ -43,6 +43,8 @@
                #:edge-label-font (or/c #f (is-a?/c font%))
                #:edge-labels? boolean?
                #:filter (-> any/c (or/c #f string?) any/c)
+               #:x-spacing real?
+               #:y-spacing real?
                #:graph-pasteboard-mixin (make-mixin-contract graph-pasteboard<%>)
                #:reduce (-> reduction-relation? any/c
                             (listof (list/c (or/c false/c string?) any/c))))
@@ -62,6 +64,8 @@
                   #:edge-label-font (or/c #f (is-a?/c font%))
                   #:edge-labels? boolean?
                   #:filter (-> any/c (or/c #f string?) any/c)
+                  #:x-spacing real?
+                  #:y-spacing real?
                   #:graph-pasteboard-mixin (make-mixin-contract graph-pasteboard<%>)
                   #:reduce (-> reduction-relation? any/c
                                (listof (list/c (or/c false/c string?) any/c)))