diff --git a/net/sunrpc/auth_unix.c b/net/sunrpc/auth_unix.c
index 4cb70dc..e50502d 100644
--- a/net/sunrpc/auth_unix.c
+++ b/net/sunrpc/auth_unix.c
@@ -129,6 +129,9 @@
 	for (i = 0; i < groups ; i++)
 		if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i))
 			return 0;
+	if (groups < NFS_NGROUPS &&
+	    cred->uc_gids[groups] != NOGROUP)
+		return 0;
 	return 1;
 }