diff --git a/README.md b/README.md
index 4a4c561..d844638 100644
--- a/README.md
+++ b/README.md
@@ -171,7 +171,7 @@ Run `M-x customize-group RET doom-modeline RET` or set the variables.
 
 ;; The limit of the window width.
 ;; If `window-width' is smaller than the limit, some information won't be displayed.
-(setq doom-modeline-window-width-limit (+ fill-column 20))
+(setq doom-modeline-window-width-limit fill-column
 
 ;; How to detect the project root.
 ;; The default priority of detection is `ffip' > `projectile' > `project'.
diff --git a/doom-modeline-core.el b/doom-modeline-core.el
index 019edaa..787de90 100644
--- a/doom-modeline-core.el
+++ b/doom-modeline-core.el
@@ -147,7 +147,7 @@ If the actual char height is larger, it respects the actual char height."
          (set sym (if (> val 0) val 1)))
   :group 'doom-modeline)
 
-(defcustom doom-modeline-window-width-limit (+ fill-column 20)
+(defcustom doom-modeline-window-width-limit fill-column
   "The limit of the window width.
 
 If `window-width' is smaller than the limit, some information won't be displayed."