diff --git a/include/libvirt/libvirt-nwfilter.h b/include/libvirt/libvirt-nwfilter.h
index 041b1fc33b..9897df6df6 100644
--- a/include/libvirt/libvirt-nwfilter.h
+++ b/include/libvirt/libvirt-nwfilter.h
@@ -80,6 +80,10 @@ virNWFilterPtr          virNWFilterLookupByUUID       (virConnectPtr conn,
 virNWFilterPtr          virNWFilterLookupByUUIDString (virConnectPtr conn,
                                                        const char *uuid);
 
+typedef enum {
+    VIR_NWFILTER_DEFINE_VALIDATE = 1 << 0, /* Validate the XML document against schema */
+} virNWFilterDefineFlags;
+
 /*
  * Define persistent nwfilter
  */
diff --git a/src/libvirt-nwfilter.c b/src/libvirt-nwfilter.c
index bd583ee682..7b857d1422 100644
--- a/src/libvirt-nwfilter.c
+++ b/src/libvirt-nwfilter.c
@@ -410,7 +410,7 @@ virNWFilterDefineXML(virConnectPtr conn, const char *xmlDesc)
  * virNWFilterDefineXMLFlags:
  * @conn: pointer to the hypervisor connection
  * @xmlDesc: an XML description of the nwfilter
- * @flags: extra flags; not used yet, so callers should always pass 0
+ * @flags: bitwise-OR of virNWFilterDefineFlags
  *
  * Define a new network filter, based on an XML description
  * similar to the one returned by virNWFilterGetXMLDesc()