diff --git a/lisp/emacs-lisp/cl-lib.el b/lisp/emacs-lisp/cl-lib.el
index f1b3b8fdbcc..07f37410d3f 100644
--- a/lisp/emacs-lisp/cl-lib.el
+++ b/lisp/emacs-lisp/cl-lib.el
@@ -486,7 +486,7 @@ Thus, `(cl-list* A B C D)' is equivalent to `(nconc (list A B C) D)', or to
 (defun cl-copy-list (list)
   "Return a copy of LIST, which may be a dotted list.
 The elements of LIST are not copied, just the list structure itself."
-  (declare (side-effect-free error-free))
+  (declare (side-effect-free t))
   (if (consp list)
       (let ((res nil))
 	(while (consp list) (push (pop list) res))