diff --git a/build.go b/build.go
index 0a23ebf..376a31d 100644
--- a/build.go
+++ b/build.go
@@ -1,4 +1,33 @@
-// +build ignore
+// BSD 2-Clause License
+//
+// Copyright (c) 2016-2018, Alexander Neumann <alexander@bumpern.de>
+// All rights reserved.
+//
+// This file has been copied from the repository at:
+// https://github.com/fd0/build-go
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// * Redistributions of source code must retain the above copyright notice, this
+//   list of conditions and the following disclaimer.
+//
+// * Redistributions in binary form must reproduce the above copyright notice,
+//   this list of conditions and the following disclaimer in the documentation
+//   and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// +build ignore_build_go
 
 package main
 
@@ -15,20 +44,8 @@ import (
 	"strings"
 )
 
-var (
-	verbose    bool
-	keepGopath bool
-	runTests   bool
-	enableCGO  bool
-)
-
-var config = struct {
-	Name       string
-	Namespace  string
-	Main       string
-	Tests      []string
-	MinVersion GoVersion
-}{
+// config contains the configuration for the program to build.
+var config = Config{
 	Name:       "rest-server",                                   // name of the program executable and directory
 	Namespace:  "github.com/restic/rest-server",                 // subdir of GOPATH, e.g. "github.com/foo/bar"
 	Main:       "github.com/restic/rest-server/cmd/rest-server", // package name for the main package
@@ -36,6 +53,22 @@ var config = struct {
 	MinVersion: GoVersion{Major: 1, Minor: 7, Patch: 0},         // minimum Go version supported
 }
 
+// Config configures the build.
+type Config struct {
+	Name       string
+	Namespace  string
+	Main       string
+	Tests      []string
+	MinVersion GoVersion
+}
+
+var (
+	verbose    bool
+	keepGopath bool
+	runTests   bool
+	enableCGO  bool
+)
+
 // specialDir returns true if the file begins with a special character ('.' or '_').
 func specialDir(name string) bool {
 	if name == "." {