diff --git a/yasnippet-tests.el b/yasnippet-tests.el
index cdb781a..783eb38 100644
--- a/yasnippet-tests.el
+++ b/yasnippet-tests.el
@@ -260,11 +260,12 @@ TODO: correct this bug!"
 (defmacro yas-with-overriden-buffer-list (&rest body)
   (let ((saved-sym (gensym)))
     `(let ((,saved-sym (symbol-function 'buffer-list)))
-       (cl-flet ((buffer-list ()
-                              (remove-if #'(lambda (buf)
-                                             (with-current-buffer buf
-                                               (eq major-mode 'lisp-interaction-mode)))
-                                         (funcall ,saved-sym))))
+       (yas--with-temporary-redefinitions
+           ((buffer-list ()
+                         (remove-if #'(lambda (buf)
+                                        (with-current-buffer buf
+                                          (eq major-mode 'lisp-interaction-mode)))
+                                    (funcall ,saved-sym))))
          ,@body))))
 
 (defmacro yas-with-some-interesting-snippet-dirs (&rest body)
@@ -474,9 +475,10 @@ TODO: be meaner"
 (defun yas/ert ()
   (interactive)
   (with-temp-buffer
-    (cl-flet ((message (&rest args)        ;
-                       (declare (ignore args))
-                       nil))
+    (yas--with-temporary-redefinitions
+        ((message (&rest args)        ;
+                  (declare (ignore args))
+                  nil))
       (ert t (buffer-name (current-buffer)))
       (princ (buffer-string)))))