diff --git a/lisp/faces.el b/lisp/faces.el
index 728f8b0fe67..7355e1dd0a5 100644
--- a/lisp/faces.el
+++ b/lisp/faces.el
@@ -2578,7 +2578,7 @@ non-nil."
   :group 'basic-faces)
 
 (defface mode-line-highlight
-  '((((class color) (min-colors 88))
+  '((((supports :box t) (class color) (min-colors 88))
      :box (:line-width 2 :color "grey40" :style released-button))
     (t
      :inherit highlight))