diff --git a/metropolis/cli/metroctl/rpc.go b/metropolis/cli/metroctl/rpc.go
index 06008e3..cab6d4f 100644
--- a/metropolis/cli/metroctl/rpc.go
+++ b/metropolis/cli/metroctl/rpc.go
@@ -18,7 +18,7 @@
 	// Collect credentials, validate command parameters, and try dialing the
 	// cluster.
 	ocert, opkey, err := core.GetOwnerCredentials(flags.configPath)
-	if errors.Is(err, core.NoCredentialsError) {
+	if errors.Is(err, core.ErrNoCredentials) {
 		log.Fatalf("You have to take ownership of the cluster first: %v", err)
 	}
 	if len(flags.clusterEndpoints) == 0 {
@@ -52,7 +52,7 @@
 	// Collect credentials, validate command parameters, and try dialing the
 	// cluster.
 	ocert, opkey, err := core.GetOwnerCredentials(flags.configPath)
-	if errors.Is(err, core.NoCredentialsError) {
+	if errors.Is(err, core.ErrNoCredentials) {
 		log.Fatalf("You have to take ownership of the cluster first: %v", err)
 	}
 	cc, err := core.DialNode(ctx, opkey, ocert, cacert, flags.proxyAddr, id, address)