diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index 99e84e23ad8..2fff0bd4a5f 100644
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -343,7 +343,7 @@ Same format as `byte-optimize--lexvars', with shared structure and contents.")
       (numberp expr)
       (stringp expr)
       (and (consp expr)
-           (eq (car expr) 'quote)
+           (memq (car expr) '(quote function))
            (symbolp (cadr expr)))
       (keywordp expr)))