diff --git a/lisp/cus-start.el b/lisp/cus-start.el
index f5b70e082a5..3fd6ac031c0 100644
--- a/lisp/cus-start.el
+++ b/lisp/cus-start.el
@@ -73,9 +73,11 @@
        '(choice
          (const :tag "Frame default" t)
          (const :tag "Filled box" box)
+         (cons :tag "Box with specified size"
+               (const box) integer)
          (const :tag "Hollow cursor" hollow)
          (const :tag "Vertical bar" bar)
-         (cons  :tag "Vertical bar with specified width"
+         (cons  :tag "Vertical bar with specified height"
                 (const bar) integer)
          (const :tag "Horizontal bar" hbar)
          (cons  :tag "Horizontal bar with specified width"
@@ -627,7 +629,9 @@ since it could result in memory overflow and make Emacs crash."
 	     (scroll-margin windows integer)
              (maximum-scroll-margin windows float "26.1")
 	     (hscroll-margin windows integer "22.1")
-	     (hscroll-step windows number "22.1")
+	     (hscroll-step windows
+                           (choice (const :tag "Center horizontally" nil)
+                                   number) "22.1")
 	     (truncate-partial-width-windows
 	      display
 	      (choice (integer :tag "Truncate if narrower than")
@@ -787,7 +791,11 @@ since it could result in memory overflow and make Emacs crash."
               "27.1"
               :safe (lambda (value) (or (characterp value) (null value))))
 	     ;; xfaces.c
-	     (scalable-fonts-allowed display boolean "22.1")
+	     (scalable-fonts-allowed
+              display (choice (const :tag "Don't allow scalable fonts" nil)
+                              (const :tag "Allow any scalable font" t)
+                              (repeat regexp))
+              "22.1")
 	     ;; xfns.c
 	     (x-bitmap-file-path installation
 				 (repeat (directory :format "%v")))