diff --git a/api/version.go b/api/version.go
index 6ea04cf..8dc65da 100644
--- a/api/version.go
+++ b/api/version.go
@@ -1,3 +1,18 @@
+// Copyright (C) 2020 Graylog, Inc.
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the Server Side Public License, version 1,
+// as published by MongoDB, Inc.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// Server Side Public License for more details.
+//
+// You should have received a copy of the Server Side Public License
+// along with this program. If not, see
+// <http://www.mongodb.com/licensing/server-side-public-license>.
+
 package api
 
 import "github.com/hashicorp/go-version"
diff --git a/common/sigar.go b/common/sigar.go
index a4e7736..683fd4e 100644
--- a/common/sigar.go
+++ b/common/sigar.go
@@ -13,7 +13,7 @@
 // along with this program. If not, see
 // <http://www.mongodb.com/licensing/server-side-public-license>.
 
-// +build !freebsd,!darwin,!solaris
+//go:build !freebsd && !darwin && !solaris
 
 package common
 
diff --git a/daemon/svc_helper.go b/daemon/svc_helper.go
index 154ca0a..ce96fbf 100644
--- a/daemon/svc_helper.go
+++ b/daemon/svc_helper.go
@@ -13,7 +13,7 @@
 // along with this program. If not, see
 // <http://www.mongodb.com/licensing/server-side-public-license>.
 
-// +build !windows
+//go:build !windows
 
 package daemon
 
diff --git a/services/control_handler_unix.go b/services/control_handler_unix.go
index a8477fe..fe92e96 100644
--- a/services/control_handler_unix.go
+++ b/services/control_handler_unix.go
@@ -13,7 +13,7 @@
 // along with this program. If not, see
 // <http://www.mongodb.com/licensing/server-side-public-license>.
 
-// +build darwin linux solaris freebsd
+//go:build darwin || linux || solaris || freebsd
 
 package services