diff --git a/src/vnet/pg/pg.h b/src/vnet/pg/pg.h
index c0e000f..aef7a5b 100644
--- a/src/vnet/pg/pg.h
+++ b/src/vnet/pg/pg.h
@@ -299,6 +299,8 @@
   /* Identifies stream for this interface. */
   u32 id;
 
+  u8 gso_enabled;
+  u32 gso_size;
   pcap_main_t pcap_main;
   u8 *pcap_file_name;
 } pg_interface_t;
@@ -351,7 +353,8 @@
 			       int is_enable);
 
 /* Find/create free packet-generator interface index. */
-u32 pg_interface_add_or_get (pg_main_t * pg, uword stream_index);
+u32 pg_interface_add_or_get (pg_main_t * pg, uword stream_index,
+			     u8 gso_enabled, u32 gso_size);
 
 always_inline pg_node_t *
 pg_get_node (uword node_index)