diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index a366107a7331ad36864ba81b8b14ba940756ac70..2d7525fbcf250225981ab521da638fc8f2a204d5 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1942,6 +1942,7 @@ static int nfs23_validate_mount_data(void *options,
 		args->namlen		= data->namlen;
 		args->bsize		= data->bsize;
 
+		args->auth_flavors[0] = RPC_AUTH_UNIX;
 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
 			args->auth_flavors[0] = data->pseudoflavor;
 		if (!args->nfs_server.hostname)
@@ -2637,6 +2638,7 @@ static int nfs4_validate_mount_data(void *options,
 			goto out_no_address;
 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
 
+		args->auth_flavors[0] = RPC_AUTH_UNIX;
 		if (data->auth_flavourlen) {
 			if (data->auth_flavourlen > 1)
 				goto out_inval_auth;