diff --git a/devstack/local.conf.sample b/devstack/local.conf.sample
index ecf88883..73ea7f63 100644
--- a/devstack/local.conf.sample
+++ b/devstack/local.conf.sample
@@ -76,11 +76,16 @@ disable_service cinder c-sch c-api c-vol
 # Default value is leastloaded.
 #OVN_L3_SCHEDULER=leastloaded
 
-# Whether or not to build custom openvswitch kernel modules from the ovs git
-# tree. This is enabled by default.  This is required unless your distro kernel
-# includes ovs+conntrack support.  This support was first released in Linux 4.3,
-# and will likely be backported by some distros.
-#OVN_BUILD_MODULES=False
+# The DevStack plugin defaults to using the ovn branch from the official ovs
+# repo.  You can optionally use a different one.  For example, you may want to
+# use the latest patches in blp's ovn branch (and see OVN_BUILD_FROM_SOURCE):
+#OVN_REPO=https://github.com/blp/ovs-reviews.git
+#OVN_BRANCH=ovn
+
+# NOTE: When specifying the branch, as shown above, you must also enable this!
+# By default, OVN will be installed from packages. In order to build OVN from
+# source, set OVN_BUILD_FROM_SOURCE=True
+#OVN_BUILD_FROM_SOURCE=False
 
 # If the admin wants to enable this chassis to host gateway routers for
 # external connectivity, then set ENABLE_CHASSIS_AS_GW to True.