diff --git a/src/plugins/nat/nat.c b/src/plugins/nat/nat.c
index 0d909ce..9eb0384 100755
--- a/src/plugins/nat/nat.c
+++ b/src/plugins/nat/nat.c
@@ -830,6 +830,7 @@
 	{
 	  fib_index = sm->inside_fib_index;
 	  vrf_id = sm->inside_vrf_id;
+	  fib_table_lock (fib_index, FIB_PROTOCOL_IP4, FIB_SOURCE_PLUGIN_LOW);
 	}
 
       if (!(out2in_only || identity_nat))
diff --git a/src/vnet/interface.api b/src/vnet/interface.api
index 8c700e1..d30f1c2 100644
--- a/src/vnet/interface.api
+++ b/src/vnet/interface.api
@@ -247,7 +247,7 @@
     @param context - sender context, to match reply w/ request
     @param sw_if_index - index of the interface
     @param is_ipv6 - if non-zero ipv6, else ipv4
-    @param vrf_id - fib table/vrd id to associate the interface with
+    @param vrf_id - fib table/vrf id to associate the interface with
 */
 autoreply define sw_interface_set_table
 {