`((,(concat "^\\(" (regexp-quote mail-header-separator) "\\)$")
               1 'message-separator-face))
          nil)
-      (,(lambda (limit)
-         (re-search-forward (concat "^\\("
-                                    message-cite-prefix-regexp
-                                    "\\).*")
-                            limit t))
+      ((lambda (limit)
+        (re-search-forward (concat "^\\("
+                                   message-cite-prefix-regexp
+                                   "\\).*")
+                           limit t))
        (0 'message-cited-text-face))
       (,mime-edit-tag-regexp
        (0 'message-mml-face))))