diff --git a/etc/xen-tools.conf b/etc/xen-tools.conf
index 7529a76..e5c981e 100644
--- a/etc/xen-tools.conf
+++ b/etc/xen-tools.conf
@@ -80,6 +80,7 @@ memory = 128Mb    # Memory size
 swap   = 128Mb    # Swap size
 fs     = ext3     # use EXT3 filesystems
 dist   = sarge    # Default distribution to install.
+image  = sparse   # Specify sparse vs. full disk images.
 
 #
 #  Currently supported and tested distributions include: