diff --git a/README.md b/README.md
index f40e311..3a5161a 100644
--- a/README.md
+++ b/README.md
@@ -104,7 +104,7 @@ Upgrading via your distribution's package repository is preferred.
 
 If upgrading manually, same with installation above by running:
 
-    #sudo python setup.py install -force
+    #sudo python setup.py install --force
 
 Restart waagent service,for most of linux distributions: