diff --git a/CHANGES.md b/CHANGES.md
index 22fbbeef..44e40159 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -32,7 +32,8 @@
   * `XMonad.Hooks.BorderPerWindow`
 
     While XMonad provides config to set all window borders at the same
-    width, this extension defines and sets border width for each window.
+    width, this extension lets user set border width for a specific window
+    using a ManageHook.
 
   * `XMonad.Util.Parser`
 
diff --git a/XMonad/Hooks/BorderPerWindow.hs b/XMonad/Hooks/BorderPerWindow.hs
index 17beaf4b..4c1927b2 100644
--- a/XMonad/Hooks/BorderPerWindow.hs
+++ b/XMonad/Hooks/BorderPerWindow.hs
@@ -1,7 +1,7 @@
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  XMonad.Hooks.BorderPerWindow
--- Description :  Set border width for each window in all layouts.
+-- Description :  Set border width for a window in a ManageHook.
 -- Copyright   :  (c) 2021 Xiaokui Shu
 -- License     :  BSD-style (see LICENSE)
 --