diff --git a/atom/browser/api/lib/dialog.coffee b/atom/browser/api/lib/dialog.coffee
index 6ee334e29a53..61547affa2d4 100644
--- a/atom/browser/api/lib/dialog.coffee
+++ b/atom/browser/api/lib/dialog.coffee
@@ -101,12 +101,6 @@ module.exports =
           options.cancelId = i
           break
 
-    # On OS X the "Cancel" is always get selected when dialog is cancelled.
-    if process.platform is 'darwin'
-      for text, i in options.buttons when text is 'Cancel'
-        options.cancelId = i
-        break
-
     binding.showMessageBox messageBoxType,
                            options.buttons,
                            options.cancelId,
diff --git a/docs/api/dialog.md b/docs/api/dialog.md
index 2023809b54ba..9e123b381c51 100644
--- a/docs/api/dialog.md
+++ b/docs/api/dialog.md
@@ -79,8 +79,8 @@ will be passed via `callback(filename)`
   * `cancelId` Integer - The value will be returned when user cancels the dialog
     instead of clicking the buttons of the dialog. By default it is the index
     of the buttons that have "cancel" or "no" as label, or 0 if there is no such
-    buttons. On OS X the index of "Cancel" button will always be used as
-    `cancelId`, not matter whether it is already specified.
+    buttons. On OS X and Windows the index of "Cancel" button will always be
+    used as `cancelId`, not matter whether it is already specified.
 * `callback` Function
 
 Shows a message box, it will block until the message box is closed. It returns