diff --git a/fs/nfs/netns.h b/fs/nfs/netns.h
index 1538d3a..137238b 100644
--- a/fs/nfs/netns.h
+++ b/fs/nfs/netns.h
@@ -23,6 +23,7 @@
 #if IS_ENABLED(CONFIG_NFS_V4)
 	struct idr cb_ident_idr; /* Protected by nfs_client_lock */
 	unsigned short nfs_callback_tcpport;
+	unsigned short nfs_callback_tcpport6;
 #endif
 	spinlock_t nfs_client_lock;
 	struct timespec boot_time;