diff --git a/core/core-ui.el b/core/core-ui.el
index 71f75c035..a3498cf4f 100644
--- a/core/core-ui.el
+++ b/core/core-ui.el
@@ -138,10 +138,11 @@ size.")
 e.g. If you indent with spaces by default, tabs will be highlighted. If you
 indent with tabs, spaces at BOL are highlighted.
 
-Does nothing if `whitespace-mode' is already active or the current buffer is
-read-only or not file-visiting."
+Does nothing if `whitespace-mode' or 'global-whitespace-mode' is already 
+active or if the current buffer is read-only or not file-visiting."
   (unless (or (eq major-mode 'fundamental-mode)
               buffer-read-only
+              global-whitespace-mode
               (null buffer-file-name))
     (require 'whitespace)
     (set (make-local-variable 'whitespace-style)