diff --git a/pkg/cmd/register/register.go b/pkg/cmd/register/register.go
index e4c8367b..0f17d6a9 100644
--- a/pkg/cmd/register/register.go
+++ b/pkg/cmd/register/register.go
@@ -292,6 +292,14 @@ func runRegisterSteps(ctx context.Context, t *terminal.Terminal, s RegisterStore
 		NodeSpec:       toProtoNodeSpec(hwProfile),
 	}))
 	if err != nil {
+		// Newer dev-plane returns CodeAlreadyExists for a duplicate node name.
+		// Older dev-plane leaks the raw Postgres unique-constraint error, so we
+		// also match the constraint name for backwards compatibility until the
+		// server change is fully rolled out.
+		if connect.CodeOf(err) == connect.CodeAlreadyExists ||
+			strings.Contains(err.Error(), "externalnode_organization_id_name") {
+			return nil, fmt.Errorf("a node with this name already exists")
+		}
 		return nil, fmt.Errorf("failed to register node: %w", err)
 	}