diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 416f32e34a33..08746ec1d44a 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3111,10 +3111,11 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
 	/*
 	 * We try hard to give out unique clientid's, so if we get an
 	 * attempt to confirm the same clientid with a different cred,
-	 * there's a bug somewhere.  Let's charitably assume it's our
-	 * bug.
+	 * the client may be buggy; this should never happen.
+	 *
+	 * Nevertheless, RFC 7530 recommends INUSE for this case:
 	 */
-	status = nfserr_serverfault;
+	status = nfserr_clid_inuse;
 	if (unconf && !same_creds(&unconf->cl_cred, &rqstp->rq_cred))
 		goto out;
 	if (conf && !same_creds(&conf->cl_cred, &rqstp->rq_cred))