diff --git a/vendor/cmd/go/internal/modconv/dep.go b/vendor/cmd/go/internal/modconv/dep.go
index 28dd28a..690c206 100644
--- a/vendor/cmd/go/internal/modconv/dep.go
+++ b/vendor/cmd/go/internal/modconv/dep.go
@@ -9,11 +9,13 @@
 	"strconv"
 	"strings"
 
+	"cmd/go/internal/modfile"
 	"cmd/go/internal/module"
 	"cmd/go/internal/semver"
 )
 
-func ParseGopkgLock(file string, data []byte) ([]module.Version, error) {
+func ParseGopkgLock(file string, data []byte) (*modfile.File, error) {
+	mf := new(modfile.File)
 	var list []module.Version
 	var r *module.Version
 	for lineno, line := range strings.Split(string(data), "\n") {
@@ -66,6 +68,7 @@
 		if r.Path == "" || r.Version == "" {
 			return nil, fmt.Errorf("%s: empty [[projects]] stanza (%s)", file, r.Path)
 		}
+		mf.Require = append(mf.Require, &modfile.Require{Mod: r})
 	}
-	return list, nil
+	return mf, nil
 }
diff --git a/vendor/cmd/go/internal/modconv/glide.go b/vendor/cmd/go/internal/modconv/glide.go
index abe88c4..3bc675f 100644
--- a/vendor/cmd/go/internal/modconv/glide.go
+++ b/vendor/cmd/go/internal/modconv/glide.go
@@ -5,12 +5,14 @@
 package modconv
 
 import (
-	"cmd/go/internal/module"
 	"strings"
+
+	"cmd/go/internal/modfile"
+	"cmd/go/internal/module"
 )
 
-func ParseGlideLock(file string, data []byte) ([]module.Version, error) {
-	var list []module.Version
+func ParseGlideLock(file string, data []byte) (*modfile.File, error) {
+	mf := new(modfile.File)
 	imports := false
 	name := ""
 	for lineno, line := range strings.Split(string(data), "\n") {
@@ -32,9 +34,9 @@
 		if strings.HasPrefix(line, "  version:") {
 			version := strings.TrimSpace(line[len("  version:"):])
 			if name != "" && version != "" {
-				list = append(list, module.Version{Path: name, Version: version})
+				mf.Require = append(mf.Require, &modfile.Require{Mod: module.Version{Path: name, Version: version}})
 			}
 		}
 	}
-	return list, nil
+	return mf, nil
 }
diff --git a/vendor/cmd/go/internal/modconv/glock.go b/vendor/cmd/go/internal/modconv/glock.go
index 57eb66e..1b786a9 100644
--- a/vendor/cmd/go/internal/modconv/glock.go
+++ b/vendor/cmd/go/internal/modconv/glock.go
@@ -7,17 +7,18 @@
 import (
 	"strings"
 
+	"cmd/go/internal/modfile"
 	"cmd/go/internal/module"
 )
 
-func ParseGLOCKFILE(file string, data []byte) ([]module.Version, error) {
-	var list []module.Version
+func ParseGLOCKFILE(file string, data []byte) (*modfile.File, error) {
+	mf := new(modfile.File)
 	for lineno, line := range strings.Split(string(data), "\n") {
 		lineno++
 		f := strings.Fields(line)
 		if len(f) >= 2 && f[0] != "cmd" {
-			list = append(list, module.Version{Path: f[0], Version: f[1]})
+			mf.Require = append(mf.Require, &modfile.Require{Mod: module.Version{Path: f[0], Version: f[1]}})
 		}
 	}
-	return list, nil
+	return mf, nil
 }
diff --git a/vendor/cmd/go/internal/modconv/godeps.go b/vendor/cmd/go/internal/modconv/godeps.go
index 904fd70..6398dbe 100644
--- a/vendor/cmd/go/internal/modconv/godeps.go
+++ b/vendor/cmd/go/internal/modconv/godeps.go
@@ -7,10 +7,11 @@
 import (
 	"encoding/json"
 
+	"cmd/go/internal/modfile"
 	"cmd/go/internal/module"
 )
 
-func ParseGodepsJSON(file string, data []byte) ([]module.Version, error) {
+func ParseGodepsJSON(file string, data []byte) (*modfile.File, error) {
 	var cfg struct {
 		ImportPath string
 		Deps       []struct {
@@ -21,9 +22,9 @@
 	if err := json.Unmarshal(data, &cfg); err != nil {
 		return nil, err
 	}
-	var list []module.Version
+	mf := new(modfile.File)
 	for _, d := range cfg.Deps {
-		list = append(list, module.Version{Path: d.ImportPath, Version: d.Rev})
+		mf.Require = append(mf.Require, &modfile.Require{Mod: module.Version{Path: d.ImportPath, Version: d.Rev}})
 	}
-	return list, nil
+	return mf, nil
 }
diff --git a/vendor/cmd/go/internal/modconv/modconv.go b/vendor/cmd/go/internal/modconv/modconv.go
index b689b52..5cc61a8 100644
--- a/vendor/cmd/go/internal/modconv/modconv.go
+++ b/vendor/cmd/go/internal/modconv/modconv.go
@@ -4,9 +4,9 @@
 
 package modconv
 
-import "cmd/go/internal/module"
+import "cmd/go/internal/modfile"
 
-var Converters = map[string]func(string, []byte) ([]module.Version, error){
+var Converters = map[string]func(string, []byte) (*modfile.File, error){
 	"GLOCKFILE":          ParseGLOCKFILE,
 	"Godeps/Godeps.json": ParseGodepsJSON,
 	"Gopkg.lock":         ParseGopkgLock,
diff --git a/vendor/cmd/go/internal/modconv/modconv_test.go b/vendor/cmd/go/internal/modconv/modconv_test.go
index 5defacd..353161b 100644
--- a/vendor/cmd/go/internal/modconv/modconv_test.go
+++ b/vendor/cmd/go/internal/modconv/modconv_test.go
@@ -55,8 +55,8 @@
 				t.Error(err)
 			}
 			var buf bytes.Buffer
-			for _, r := range out {
-				fmt.Fprintf(&buf, "%s %s\n", r.Path, r.Version)
+			for _, r := range out.Require {
+				fmt.Fprintf(&buf, "%s %s\n", r.Mod.Path, r.Mod.Version)
 			}
 			if !bytes.Equal(buf.Bytes(), want) {
 				t.Errorf("have:\n%s\nwant:\n%s", buf.Bytes(), want)
diff --git a/vendor/cmd/go/internal/modconv/tsv.go b/vendor/cmd/go/internal/modconv/tsv.go
index fd33649..feba181 100644
--- a/vendor/cmd/go/internal/modconv/tsv.go
+++ b/vendor/cmd/go/internal/modconv/tsv.go
@@ -7,17 +7,18 @@
 import (
 	"strings"
 
+	"cmd/go/internal/modfile"
 	"cmd/go/internal/module"
 )
 
-func ParseDependenciesTSV(file string, data []byte) ([]module.Version, error) {
-	var list []module.Version
+func ParseDependenciesTSV(file string, data []byte) (*modfile.File, error) {
+	mf := new(modfile.File)
 	for lineno, line := range strings.Split(string(data), "\n") {
 		lineno++
 		f := strings.Split(line, "\t")
 		if len(f) >= 3 {
-			list = append(list, module.Version{Path: f[0], Version: f[2]})
+			mf.Require = append(mf.Require, &modfile.Require{Mod: module.Version{Path: f[0], Version: f[2]}})
 		}
 	}
-	return list, nil
+	return mf, nil
 }
diff --git a/vendor/cmd/go/internal/modconv/vconf.go b/vendor/cmd/go/internal/modconv/vconf.go
index 5d3cd3c..a9a8e62 100644
--- a/vendor/cmd/go/internal/modconv/vconf.go
+++ b/vendor/cmd/go/internal/modconv/vconf.go
@@ -7,11 +7,12 @@
 import (
 	"strings"
 
+	"cmd/go/internal/modfile"
 	"cmd/go/internal/module"
 )
 
-func ParseVendorConf(file string, data []byte) ([]module.Version, error) {
-	var list []module.Version
+func ParseVendorConf(file string, data []byte) (*modfile.File, error) {
+	mf := new(modfile.File)
 	for lineno, line := range strings.Split(string(data), "\n") {
 		lineno++
 		if i := strings.Index(line, "#"); i >= 0 {
@@ -19,8 +20,8 @@
 		}
 		f := strings.Fields(line)
 		if len(f) >= 2 {
-			list = append(list, module.Version{Path: f[0], Version: f[1]})
+			mf.Require = append(mf.Require, &modfile.Require{Mod: module.Version{Path: f[0], Version: f[1]}})
 		}
 	}
-	return list, nil
+	return mf, nil
 }
diff --git a/vendor/cmd/go/internal/modconv/vjson.go b/vendor/cmd/go/internal/modconv/vjson.go
index 38b0a68..eec86b7 100644
--- a/vendor/cmd/go/internal/modconv/vjson.go
+++ b/vendor/cmd/go/internal/modconv/vjson.go
@@ -7,10 +7,11 @@
 import (
 	"encoding/json"
 
+	"cmd/go/internal/modfile"
 	"cmd/go/internal/module"
 )
 
-func ParseVendorJSON(file string, data []byte) ([]module.Version, error) {
+func ParseVendorJSON(file string, data []byte) (*modfile.File, error) {
 	var cfg struct {
 		Package []struct {
 			Path     string
@@ -20,9 +21,9 @@
 	if err := json.Unmarshal(data, &cfg); err != nil {
 		return nil, err
 	}
-	var list []module.Version
+	mf := new(modfile.File)
 	for _, d := range cfg.Package {
-		list = append(list, module.Version{Path: d.Path, Version: d.Revision})
+		mf.Require = append(mf.Require, &modfile.Require{Mod: module.Version{Path: d.Path, Version: d.Revision}})
 	}
-	return list, nil
+	return mf, nil
 }
diff --git a/vendor/cmd/go/internal/modconv/vmanifest.go b/vendor/cmd/go/internal/modconv/vmanifest.go
index f2cf0f5..c0ef2a9 100644
--- a/vendor/cmd/go/internal/modconv/vmanifest.go
+++ b/vendor/cmd/go/internal/modconv/vmanifest.go
@@ -7,10 +7,11 @@
 import (
 	"encoding/json"
 
+	"cmd/go/internal/modfile"
 	"cmd/go/internal/module"
 )
 
-func ParseVendorManifest(file string, data []byte) ([]module.Version, error) {
+func ParseVendorManifest(file string, data []byte) (*modfile.File, error) {
 	var cfg struct {
 		Dependencies []struct {
 			ImportPath string
@@ -20,9 +21,9 @@
 	if err := json.Unmarshal(data, &cfg); err != nil {
 		return nil, err
 	}
-	var list []module.Version
+	mf := new(modfile.File)
 	for _, d := range cfg.Dependencies {
-		list = append(list, module.Version{Path: d.ImportPath, Version: d.Revision})
+		mf.Require = append(mf.Require, &modfile.Require{Mod: module.Version{Path: d.ImportPath, Version: d.Revision}})
 	}
-	return list, nil
+	return mf, nil
 }
diff --git a/vendor/cmd/go/internal/modconv/vyml.go b/vendor/cmd/go/internal/modconv/vyml.go
index e2ea9e3..0f017a3 100644
--- a/vendor/cmd/go/internal/modconv/vyml.go
+++ b/vendor/cmd/go/internal/modconv/vyml.go
@@ -5,12 +5,14 @@
 package modconv
 
 import (
-	"cmd/go/internal/module"
 	"strings"
+
+	"cmd/go/internal/modfile"
+	"cmd/go/internal/module"
 )
 
-func ParseVendorYML(file string, data []byte) ([]module.Version, error) {
-	var list []module.Version
+func ParseVendorYML(file string, data []byte) (*modfile.File, error) {
+	mf := new(modfile.File)
 	vendors := false
 	path := ""
 	for lineno, line := range strings.Split(string(data), "\n") {
@@ -32,9 +34,9 @@
 		if strings.HasPrefix(line, "  rev:") {
 			rev := strings.TrimSpace(line[len("  rev:"):])
 			if path != "" && rev != "" {
-				list = append(list, module.Version{Path: path, Version: rev})
+				mf.Require = append(mf.Require, &modfile.Require{Mod: module.Version{Path: path, Version: rev}})
 			}
 		}
 	}
-	return list, nil
+	return mf, nil
 }
diff --git a/vendor/cmd/go/internal/modfetch/convert.go b/vendor/cmd/go/internal/modfetch/convert.go
index 9e15116..bebb6ee 100644
--- a/vendor/cmd/go/internal/modfetch/convert.go
+++ b/vendor/cmd/go/internal/modfetch/convert.go
@@ -33,7 +33,7 @@
 	if convert == nil {
 		return fmt.Errorf("unknown legacy config file %s", file)
 	}
-	require, err := convert(file, data)
+	result, err := convert(file, data)
 	if err != nil {
 		return fmt.Errorf("parsing %s: %v", file, err)
 	}
@@ -41,19 +41,20 @@
 	// Convert requirements block, which may use raw SHA1 hashes as versions,
 	// to valid semver requirement list, respecting major versions.
 	var work par.Work
-	for _, r := range require {
-		if r.Path == "" {
+	for _, r := range result.Require {
+		m := r.Mod
+		if m.Path == "" {
 			continue
 		}
 
 		// TODO: Something better here.
-		if strings.HasPrefix(r.Path, "github.com/") || strings.HasPrefix(r.Path, "golang.org/x/") {
-			f := strings.Split(r.Path, "/")
+		if strings.HasPrefix(m.Path, "github.com/") || strings.HasPrefix(m.Path, "golang.org/x/") {
+			f := strings.Split(m.Path, "/")
 			if len(f) > 3 {
-				r.Path = strings.Join(f[:3], "/")
+				m.Path = strings.Join(f[:3], "/")
 			}
 		}
-		work.Add(r)
+		work.Add(m)
 	}
 
 	var (
@@ -81,5 +82,12 @@
 		f.AddNewRequire(path, need[path])
 	}
 
+	for _, r := range result.Replace {
+		err := f.AddReplace(r.Old.Path, r.Old.Version, r.New.Path, r.New.Version)
+		if err != nil {
+			return fmt.Errorf("add replace: %v", err)
+		}
+	}
+	f.Cleanup()
 	return nil
 }