diff --git a/mu4e/mu4e-vars.el b/mu4e/mu4e-vars.el
index 4469eafe..f82bac09 100644
--- a/mu4e/mu4e-vars.el
+++ b/mu4e/mu4e-vars.el
@@ -661,7 +661,8 @@ I.e. a message with the draft flag set."
   :group 'mu4e-faces)
 
 (defface mu4e-header-highlight-face
-  '((t :inherit hl-line :weight bold :underline t))
+  `((t :inherit hl-line :weight bold :underline t
+       ,@(and (>= emacs-major-version 27) '(:extend t))))
   "Face for the header at point."
   :group 'mu4e-faces)