diff --git a/modules/email/mu4e/config.el b/modules/email/mu4e/config.el
index 4f91e1486..d679ba26b 100644
--- a/modules/email/mu4e/config.el
+++ b/modules/email/mu4e/config.el
@@ -36,11 +36,11 @@
   (cond ((or (modulep! +mbsync)
              (eq +mu4e-backend 'mbsync))
          (setq mu4e-get-mail-command
-               (format "mbsync --all --config %S"
+               (concat "mbsync --all"
                        ;; XDG support was added to isync 1.5, but this lets
                        ;; users on older benefit from it sooner.
-                       (or (file-exists-p! "isyncrc" (or (getenv "XDG_CONFIG_HOME") "~/.config"))
-                           "~/.mbsyncrc"))
+                       (when-let (file (file-exists-p! "isyncrc" (or (getenv "XDG_CONFIG_HOME") "~/.config")))
+                         (format " --config %S" file)))
                mu4e-change-filenames-when-moving t))
         ((or (modulep! +offlineimap)
              (eq +mu4e-backend 'offlineimap))