diff --git a/emacs/mu4e-mark.el b/emacs/mu4e-mark.el
index 2825f1d9..c7f23883 100644
--- a/emacs/mu4e-mark.el
+++ b/emacs/mu4e-mark.el
@@ -208,7 +208,7 @@ If NO-CONFIRMATION is non-nil, don't ask user for confirmation."
 (defun mu4e-mark-unmark-all ()
   "Unmark all marked messages."
   (interactive)
-  (when (zerop (hash-table-count mu4e~mark-map))
+  (when (or (null mu4e~mark-map) (zerop (hash-table-count mu4e~mark-map)))
     (error "Nothing is marked"))
   (maphash
     (lambda (docid val)