1 files changed, 2 insertions, 1 deletions

diff --git a/lisp/progmodes/which-func.el b/lisp/progmodes/which-func.el
index 4ffcddf48bf..fef159d850f 100644
--- a/lisp/progmodes/which-func.el
+++ b/lisp/progmodes/which-func.el
@@ -198,7 +198,8 @@ and off otherwise."
                   (or (eq which-func-modes t)
                       (member major-mode which-func-modes))))))
     ;; Turn it off
-    (cancel-timer which-func-update-timer)
+    (when (timerp which-func-update-timer)
+      (cancel-timer which-func-update-timer))
     (setq which-func-update-timer nil)
     (dolist (buf (buffer-list))
       (with-current-buffer buf (setq which-func-mode nil)))))