diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index d2afcd8354ef..5a5566fa1619 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -62,6 +62,7 @@
 #include <linux/nfs_fs.h>
 #include "nfs4_fs.h"
 #include "internal.h"
+#include "netns.h"
 
 #define NFS_UINT_MAXLEN 11
 #define IDMAP_HASH_SZ          128