diff --git a/install.sh b/install.sh
index 819e31f269..4d6059e806 100755
--- a/install.sh
+++ b/install.sh
@@ -34,7 +34,9 @@ usage() {
  echo "-u: user that will run opennebula, defults to user executing install.sh"
  echo "-g: group of the user that will run opennebula, defults to user"
  echo "    executing install.sh"
- echo "-k: keep current configuration files, useful when upgrading"
+ echo "-k: keep configuration files of existing OpenNebula installation, useful"
+ echo "    when upgrading. This flag should not be set when installing" 
+ echo "    OpenNebula for the first time"
  echo "-d: target installation directory, if not defined it'd be root. Must be"
  echo "    an absolute path."
  echo "-c: install only 'occi' or 'ec2' client files"