diff --git a/protoc-gen-go/generator/generator.go b/protoc-gen-go/generator/generator.go
index be382f97bc..e0aba85f31 100644
--- a/protoc-gen-go/generator/generator.go
+++ b/protoc-gen-go/generator/generator.go
@@ -43,6 +43,7 @@ import (
 	"crypto/sha256"
 	"encoding/hex"
 	"fmt"
+	"go/build"
 	"go/parser"
 	"go/printer"
 	"go/token"
@@ -345,8 +346,7 @@ type symbol interface {
 type messageSymbol struct {
 	sym                         string
 	hasExtensions, isMessageSet bool
-	hasOneof                    bool
-	getters                     []getterSymbol
+	oneofTypes                  []string
 }
 
 type getterSymbol struct {
@@ -357,146 +357,10 @@ type getterSymbol struct {
 }
 
 func (ms *messageSymbol) GenerateAlias(g *Generator, pkg GoPackageName) {
-	remoteSym := string(pkg) + "." + ms.sym
-
-	g.P("type ", ms.sym, " ", remoteSym)
-	g.P("func (m *", ms.sym, ") Reset() { (*", remoteSym, ")(m).Reset() }")
-	g.P("func (m *", ms.sym, ") String() string { return (*", remoteSym, ")(m).String() }")
-	g.P("func (*", ms.sym, ") ProtoMessage() {}")
-	g.P("func (m *", ms.sym, ") XXX_Unmarshal(buf []byte) error ",
-		"{ return (*", remoteSym, ")(m).XXX_Unmarshal(buf) }")
-	g.P("func (m *", ms.sym, ") XXX_Marshal(b []byte, deterministic bool) ([]byte, error) ",
-		"{ return (*", remoteSym, ")(m).XXX_Marshal(b, deterministic) }")
-	g.P("func (m *", ms.sym, ") XXX_Size() int ",
-		"{ return (*", remoteSym, ")(m).XXX_Size() }")
-	g.P("func (m *", ms.sym, ") XXX_DiscardUnknown() ",
-		"{ (*", remoteSym, ")(m).XXX_DiscardUnknown() }")
-	if ms.hasExtensions {
-		g.P("func (*", ms.sym, ") ExtensionRangeArray() []", g.Pkg["proto"], ".ExtensionRange ",
-			"{ return (*", remoteSym, ")(nil).ExtensionRangeArray() }")
-	}
-	if ms.hasOneof {
-		// Oneofs and public imports do not mix well.
-		// We can make them work okay for the binary format,
-		// but they're going to break weirdly for text/JSON.
-		enc := "_" + ms.sym + "_OneofMarshaler"
-		dec := "_" + ms.sym + "_OneofUnmarshaler"
-		size := "_" + ms.sym + "_OneofSizer"
-		encSig := "(msg " + g.Pkg["proto"] + ".Message, b *" + g.Pkg["proto"] + ".Buffer) error"
-		decSig := "(msg " + g.Pkg["proto"] + ".Message, tag, wire int, b *" + g.Pkg["proto"] + ".Buffer) (bool, error)"
-		sizeSig := "(msg " + g.Pkg["proto"] + ".Message) int"
-		g.P("func (m *", ms.sym, ") XXX_OneofFuncs() (func", encSig, ", func", decSig, ", func", sizeSig, ", []interface{}) {")
-		g.P("_, _, _, x := (*", remoteSym, ")(nil).XXX_OneofFuncs()")
-		g.P("return ", enc, ", ", dec, ", ", size, ", x")
-		g.P("}")
-
-		g.P("func ", enc, encSig, " {")
-		g.P("m := msg.(*", ms.sym, ")")
-		g.P("m0 := (*", remoteSym, ")(m)")
-		g.P("enc, _, _, _ := m0.XXX_OneofFuncs()")
-		g.P("return enc(m0, b)")
-		g.P("}")
-
-		g.P("func ", dec, decSig, " {")
-		g.P("m := msg.(*", ms.sym, ")")
-		g.P("m0 := (*", remoteSym, ")(m)")
-		g.P("_, dec, _, _ := m0.XXX_OneofFuncs()")
-		g.P("return dec(m0, tag, wire, b)")
-		g.P("}")
-
-		g.P("func ", size, sizeSig, " {")
-		g.P("m := msg.(*", ms.sym, ")")
-		g.P("m0 := (*", remoteSym, ")(m)")
-		g.P("_, _, size, _ := m0.XXX_OneofFuncs()")
-		g.P("return size(m0)")
-		g.P("}")
-	}
-	for _, get := range ms.getters {
-
-		if get.typeName != "" {
-			g.RecordTypeUse(get.typeName)
-		}
-		typ := get.typ
-		val := "(*" + remoteSym + ")(m)." + get.name + "()"
-		if get.genType {
-			// typ will be "*pkg.T" (message/group) or "pkg.T" (enum)
-			// or "map[t]*pkg.T" (map to message/enum).
-			// The first two of those might have a "[]" prefix if it is repeated.
-			// Drop any package qualifier since we have hoisted the type into this package.
-			rep := strings.HasPrefix(typ, "[]")
-			if rep {
-				typ = typ[2:]
-			}
-			isMap := strings.HasPrefix(typ, "map[")
-			star := typ[0] == '*'
-			if !isMap { // map types handled lower down
-				typ = typ[strings.Index(typ, ".")+1:]
-			}
-			if star {
-				typ = "*" + typ
-			}
-			if rep {
-				// Go does not permit conversion between slice types where both
-				// element types are named. That means we need to generate a bit
-				// of code in this situation.
-				// typ is the element type.
-				// val is the expression to get the slice from the imported type.
-
-				ctyp := typ // conversion type expression; "Foo" or "(*Foo)"
-				if star {
-					ctyp = "(" + typ + ")"
-				}
-
-				g.P("func (m *", ms.sym, ") ", get.name, "() []", typ, " {")
-				g.In()
-				g.P("o := ", val)
-				g.P("if o == nil {")
-				g.In()
-				g.P("return nil")
-				g.Out()
-				g.P("}")
-				g.P("s := make([]", typ, ", len(o))")
-				g.P("for i, x := range o {")
-				g.In()
-				g.P("s[i] = ", ctyp, "(x)")
-				g.Out()
-				g.P("}")
-				g.P("return s")
-				g.Out()
-				g.P("}")
-				continue
-			}
-			if isMap {
-				// Split map[keyTyp]valTyp.
-				bra, ket := strings.Index(typ, "["), strings.Index(typ, "]")
-				keyTyp, valTyp := typ[bra+1:ket], typ[ket+1:]
-				// Drop any package qualifier.
-				// Only the value type may be foreign.
-				star := valTyp[0] == '*'
-				valTyp = valTyp[strings.Index(valTyp, ".")+1:]
-				if star {
-					valTyp = "*" + valTyp
-				}
-
-				typ := "map[" + keyTyp + "]" + valTyp
-				g.P("func (m *", ms.sym, ") ", get.name, "() ", typ, " {")
-				g.P("o := ", val)
-				g.P("if o == nil { return nil }")
-				g.P("s := make(", typ, ", len(o))")
-				g.P("for k, v := range o {")
-				g.P("s[k] = (", valTyp, ")(v)")
-				g.P("}")
-				g.P("return s")
-				g.P("}")
-				continue
-			}
-			// Convert imported type into the forwarding type.
-			val = "(" + typ + ")(" + val + ")"
-		}
-
-		g.P("func (m *", ms.sym, ") ", get.name, "() ", typ, " { return ", val, " }")
+	g.P("type ", ms.sym, " = ", pkg, ".", ms.sym)
+	for _, name := range ms.oneofTypes {
+		g.P("type ", name, " = ", pkg, ".", name)
 	}
-
 }
 
 type enumSymbol struct {
@@ -506,14 +370,9 @@ type enumSymbol struct {
 
 func (es enumSymbol) GenerateAlias(g *Generator, pkg GoPackageName) {
 	s := es.name
-	g.P("type ", s, " ", pkg, ".", s)
+	g.P("type ", s, " = ", pkg, ".", s)
 	g.P("var ", s, "_name = ", pkg, ".", s, "_name")
 	g.P("var ", s, "_value = ", pkg, ".", s, "_value")
-	g.P("func (x ", s, ") String() string { return (", pkg, ".", s, ")(x).String() }")
-	if !es.proto3 {
-		g.P("func (x ", s, ") Enum() *", s, "{ return (*", s, ")((", pkg, ".", s, ")(x).Enum()) }")
-		g.P("func (x *", s, ") UnmarshalJSON(data []byte) error { return (*", pkg, ".", s, ")(x).UnmarshalJSON(data) }")
-	}
 }
 
 type constOrVarSymbol struct {
@@ -1486,20 +1345,18 @@ func (g *Generator) generateImports() {
 }
 
 func (g *Generator) generateImported(id *ImportedDescriptor) {
-	// Don't generate public import symbols for files that we are generating
-	// code for, since those symbols will already be in this package.
-	// We can't simply avoid creating the ImportedDescriptor objects,
-	// because g.genFiles isn't populated at that stage.
 	tn := id.TypeName()
 	sn := tn[len(tn)-1]
 	df := id.o.File()
 	filename := *df.Name
-	for _, fd := range g.genFiles {
-		if *fd.Name == filename {
-			g.P("// Ignoring public import of ", sn, " from ", filename)
-			g.P()
-			return
-		}
+	if df.importPath == g.file.importPath {
+		// Don't generate type aliases for files in the same Go package as this one.
+		g.P("// Ignoring public import of ", sn, " from ", filename)
+		g.P()
+		return
+	}
+	if !supportTypeAliases {
+		g.Fail(fmt.Sprintf("%s: public imports require at least go1.9", filename))
 	}
 	g.P("// ", sn, " from public import ", filename)
 	g.usedPackages[df.importPath] = true
@@ -2232,6 +2089,7 @@ func (g *Generator) generateMessage(message *Descriptor) {
 		g.P("}")
 	}
 	g.P()
+	var oneofTypes []string
 	for i, field := range message.Field {
 		if field.OneofIndex == nil {
 			continue
@@ -2241,6 +2099,7 @@ func (g *Generator) generateMessage(message *Descriptor) {
 		fieldFullPath := fmt.Sprintf("%s,%d,%d", message.path, messageFieldPath, i)
 		g.P("type ", Annotate(message.file, fieldFullPath, oneofTypeName[field]), " struct{ ", Annotate(message.file, fieldFullPath, fieldNames[field]), " ", fieldTypes[field], " `", tag, "` }")
 		g.RecordTypeUse(field.GetTypeName())
+		oneofTypes = append(oneofTypes, oneofTypeName[field])
 	}
 	g.P()
 	for _, field := range message.Field {
@@ -2261,7 +2120,6 @@ func (g *Generator) generateMessage(message *Descriptor) {
 	g.P()
 
 	// Field getters
-	var getters []getterSymbol
 	for i, field := range message.Field {
 		oneof := field.OneofIndex != nil
 
@@ -2278,42 +2136,6 @@ func (g *Generator) generateMessage(message *Descriptor) {
 		}
 		fieldFullPath := fmt.Sprintf("%s,%d,%d", message.path, messageFieldPath, i)
 
-		// Only export getter symbols for basic types,
-		// and for messages and enums in the same package.
-		// Groups are not exported.
-		// Foreign types can't be hoisted through a public import because
-		// the importer may not already be importing the defining .proto.
-		// As an example, imagine we have an import tree like this:
-		//   A.proto -> B.proto -> C.proto
-		// If A publicly imports B, we need to generate the getters from B in A's output,
-		// but if one such getter returns something from C then we cannot do that
-		// because A is not importing C already.
-		var getter, genType bool
-		switch *field.Type {
-		case descriptor.FieldDescriptorProto_TYPE_GROUP:
-			getter = false
-		case descriptor.FieldDescriptorProto_TYPE_MESSAGE, descriptor.FieldDescriptorProto_TYPE_ENUM:
-			// Only export getter if its return type is in the same file.
-			//
-			// This should be the same package, not the same file.
-			// However, code elsewhere assumes that there's a 1-1 relationship
-			// between packages and files, so that's not safe.
-			//
-			// TODO: Tear out all of this complexity and just use type aliases.
-			getter = g.ObjectNamed(field.GetTypeName()).File() == message.File()
-			genType = true
-		default:
-			getter = true
-		}
-		if getter {
-			getters = append(getters, getterSymbol{
-				name:     mname,
-				typ:      typename,
-				typeName: field.GetTypeName(),
-				genType:  genType,
-			})
-		}
-
 		if field.GetOptions().GetDeprecated() {
 			g.P(deprecationComment)
 		}
@@ -2416,8 +2238,7 @@ func (g *Generator) generateMessage(message *Descriptor) {
 			sym:           ccTypeName,
 			hasExtensions: hasExtensions,
 			isMessageSet:  isMessageSet,
-			hasOneof:      len(message.OneofDecl) > 0,
-			getters:       getters,
+			oneofTypes:    oneofTypes,
 		}
 		g.file.addExport(message, ms)
 	}
@@ -3094,3 +2915,14 @@ const (
 	// tag numbers in EnumDescriptorProto
 	enumValuePath = 2 // value
 )
+
+var supportTypeAliases bool
+
+func init() {
+	for _, tag := range build.Default.ReleaseTags {
+		if tag == "go1.9" {
+			supportTypeAliases = true
+			return
+		}
+	}
+}
diff --git a/protoc-gen-go/golden_test.go b/protoc-gen-go/golden_test.go
index 70f3971246..30d2799908 100644
--- a/protoc-gen-go/golden_test.go
+++ b/protoc-gen-go/golden_test.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"flag"
 	"fmt"
+	"go/build"
 	"go/parser"
 	"go/token"
 	"io/ioutil"
@@ -38,8 +39,13 @@ func TestGolden(t *testing.T) {
 
 	// Find all the proto files we need to compile. We assume that each directory
 	// contains the files for a single package.
+	supportTypeAliases := hasReleaseTag("1.9")
 	packages := map[string][]string{}
 	err = filepath.Walk("testdata", func(path string, info os.FileInfo, err error) error {
+		if filepath.Base(path) == "import_public" && !supportTypeAliases {
+			// Public imports require type alias support.
+			return filepath.SkipDir
+		}
 		if !strings.HasSuffix(path, ".proto") {
 			return nil
 		}
@@ -405,3 +411,12 @@ func protoc(t *testing.T, args []string) {
 		t.Fatalf("protoc: %v", err)
 	}
 }
+
+func hasReleaseTag(want string) bool {
+	for _, tag := range build.Default.ReleaseTags {
+		if tag == want {
+			return true
+		}
+	}
+	return false
+}
diff --git a/protoc-gen-go/testdata/imp/imp.pb.go b/protoc-gen-go/testdata/imp/imp.pb.go
deleted file mode 100644
index e4b0a5b001..0000000000
--- a/protoc-gen-go/testdata/imp/imp.pb.go
+++ /dev/null
@@ -1,416 +0,0 @@
-// Code generated by protoc-gen-go. DO NOT EDIT.
-// source: imp/imp.proto
-
-package imp // import "github.com/golang/protobuf/protoc-gen-go/testdata/imp"
-
-import proto "github.com/golang/protobuf/proto"
-import fmt "fmt"
-import math "math"
-import imp2 "github.com/golang/protobuf/protoc-gen-go/testdata/imp/imp2"
-import imp3 "github.com/golang/protobuf/protoc-gen-go/testdata/imp/imp3"
-
-// Reference imports to suppress errors if they are not otherwise used.
-var _ = proto.Marshal
-var _ = fmt.Errorf
-var _ = math.Inf
-
-// This is a compile-time assertion to ensure that this generated file
-// is compatible with the proto package it is being compiled against.
-// A compilation error at this line likely means your copy of the
-// proto package needs to be updated.
-const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
-
-// PubliclyImportedMessage from public import imp/imp2/imp2.proto
-type PubliclyImportedMessage imp2.PubliclyImportedMessage
-
-func (m *PubliclyImportedMessage) Reset()         { (*imp2.PubliclyImportedMessage)(m).Reset() }
-func (m *PubliclyImportedMessage) String() string { return (*imp2.PubliclyImportedMessage)(m).String() }
-func (*PubliclyImportedMessage) ProtoMessage()    {}
-func (m *PubliclyImportedMessage) XXX_Unmarshal(buf []byte) error {
-	return (*imp2.PubliclyImportedMessage)(m).XXX_Unmarshal(buf)
-}
-func (m *PubliclyImportedMessage) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
-	return (*imp2.PubliclyImportedMessage)(m).XXX_Marshal(b, deterministic)
-}
-func (m *PubliclyImportedMessage) XXX_Size() int { return (*imp2.PubliclyImportedMessage)(m).XXX_Size() }
-func (m *PubliclyImportedMessage) XXX_DiscardUnknown() {
-	(*imp2.PubliclyImportedMessage)(m).XXX_DiscardUnknown()
-}
-func (m *PubliclyImportedMessage) GetField() int64 {
-	return (*imp2.PubliclyImportedMessage)(m).GetField()
-}
-
-// PubliclyImportedMessage2 from public import imp/imp2/imp2.proto
-type PubliclyImportedMessage2 imp2.PubliclyImportedMessage2
-
-func (m *PubliclyImportedMessage2) Reset() { (*imp2.PubliclyImportedMessage2)(m).Reset() }
-func (m *PubliclyImportedMessage2) String() string {
-	return (*imp2.PubliclyImportedMessage2)(m).String()
-}
-func (*PubliclyImportedMessage2) ProtoMessage() {}
-func (m *PubliclyImportedMessage2) XXX_Unmarshal(buf []byte) error {
-	return (*imp2.PubliclyImportedMessage2)(m).XXX_Unmarshal(buf)
-}
-func (m *PubliclyImportedMessage2) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
-	return (*imp2.PubliclyImportedMessage2)(m).XXX_Marshal(b, deterministic)
-}
-func (m *PubliclyImportedMessage2) XXX_Size() int {
-	return (*imp2.PubliclyImportedMessage2)(m).XXX_Size()
-}
-func (m *PubliclyImportedMessage2) XXX_DiscardUnknown() {
-	(*imp2.PubliclyImportedMessage2)(m).XXX_DiscardUnknown()
-}
-func (m *PubliclyImportedMessage2) GetField() *PubliclyImportedMessage {
-	return (*PubliclyImportedMessage)((*imp2.PubliclyImportedMessage2)(m).GetField())
-}
-
-// PubliclyImportedEnum from public import imp/imp2/imp2.proto
-type PubliclyImportedEnum imp2.PubliclyImportedEnum
-
-var PubliclyImportedEnum_name = imp2.PubliclyImportedEnum_name
-var PubliclyImportedEnum_value = imp2.PubliclyImportedEnum_value
-
-func (x PubliclyImportedEnum) String() string { return (imp2.PubliclyImportedEnum)(x).String() }
-func (x PubliclyImportedEnum) Enum() *PubliclyImportedEnum {
-	return (*PubliclyImportedEnum)((imp2.PubliclyImportedEnum)(x).Enum())
-}
-func (x *PubliclyImportedEnum) UnmarshalJSON(data []byte) error {
-	return (*imp2.PubliclyImportedEnum)(x).UnmarshalJSON(data)
-}
-
-const PubliclyImportedEnum_GLASSES = PubliclyImportedEnum(imp2.PubliclyImportedEnum_GLASSES)
-const PubliclyImportedEnum_HAIR = PubliclyImportedEnum(imp2.PubliclyImportedEnum_HAIR)
-
-type ImportedMessage_Owner int32
-
-const (
-	ImportedMessage_DAVE ImportedMessage_Owner = 1
-	ImportedMessage_MIKE ImportedMessage_Owner = 2
-)
-
-var ImportedMessage_Owner_name = map[int32]string{
-	1: "DAVE",
-	2: "MIKE",
-}
-var ImportedMessage_Owner_value = map[string]int32{
-	"DAVE": 1,
-	"MIKE": 2,
-}
-
-func (x ImportedMessage_Owner) Enum() *ImportedMessage_Owner {
-	p := new(ImportedMessage_Owner)
-	*p = x
-	return p
-}
-func (x ImportedMessage_Owner) String() string {
-	return proto.EnumName(ImportedMessage_Owner_name, int32(x))
-}
-func (x *ImportedMessage_Owner) UnmarshalJSON(data []byte) error {
-	value, err := proto.UnmarshalJSONEnum(ImportedMessage_Owner_value, data, "ImportedMessage_Owner")
-	if err != nil {
-		return err
-	}
-	*x = ImportedMessage_Owner(value)
-	return nil
-}
-func (ImportedMessage_Owner) EnumDescriptor() ([]byte, []int) {
-	return fileDescriptor_imp_6424de66809c2ae5, []int{0, 0}
-}
-
-type ImportedMessage struct {
-	Field *int64 `protobuf:"varint,1,req,name=field" json:"field,omitempty"`
-	// The forwarded getters for these fields are fiddly to get right.
-	LocalMsg   *ImportedMessage2            `protobuf:"bytes,2,opt,name=local_msg,json=localMsg" json:"local_msg,omitempty"`
-	ForeignMsg *imp3.ForeignImportedMessage `protobuf:"bytes,3,opt,name=foreign_msg,json=foreignMsg" json:"foreign_msg,omitempty"`
-	EnumField  *ImportedMessage_Owner       `protobuf:"varint,4,opt,name=enum_field,json=enumField,enum=imp.ImportedMessage_Owner" json:"enum_field,omitempty"`
-	// Types that are valid to be assigned to Union:
-	//	*ImportedMessage_State
-	Union                        isImportedMessage_Union      `protobuf_oneof:"union"`
-	Name                         []string                     `protobuf:"bytes,5,rep,name=name" json:"name,omitempty"`
-	Boss                         []ImportedMessage_Owner      `protobuf:"varint,6,rep,name=boss,enum=imp.ImportedMessage_Owner" json:"boss,omitempty"`
-	Memo                         []*ImportedMessage2          `protobuf:"bytes,7,rep,name=memo" json:"memo,omitempty"`
-	MsgMap                       map[string]*ImportedMessage2 `protobuf:"bytes,8,rep,name=msg_map,json=msgMap" json:"msg_map,omitempty" protobuf_key:"bytes,1,opt,name=key" protobuf_val:"bytes,2,opt,name=value"`
-	XXX_NoUnkeyedLiteral         struct{}                     `json:"-"`
-	proto.XXX_InternalExtensions `json:"-"`
-	XXX_unrecognized             []byte `json:"-"`
-	XXX_sizecache                int32  `json:"-"`
-}
-
-func (m *ImportedMessage) Reset()         { *m = ImportedMessage{} }
-func (m *ImportedMessage) String() string { return proto.CompactTextString(m) }
-func (*ImportedMessage) ProtoMessage()    {}
-func (*ImportedMessage) Descriptor() ([]byte, []int) {
-	return fileDescriptor_imp_6424de66809c2ae5, []int{0}
-}
-
-var extRange_ImportedMessage = []proto.ExtensionRange{
-	{Start: 90, End: 100},
-}
-
-func (*ImportedMessage) ExtensionRangeArray() []proto.ExtensionRange {
-	return extRange_ImportedMessage
-}
-func (m *ImportedMessage) XXX_Unmarshal(b []byte) error {
-	return xxx_messageInfo_ImportedMessage.Unmarshal(m, b)
-}
-func (m *ImportedMessage) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
-	return xxx_messageInfo_ImportedMessage.Marshal(b, m, deterministic)
-}
-func (dst *ImportedMessage) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_ImportedMessage.Merge(dst, src)
-}
-func (m *ImportedMessage) XXX_Size() int {
-	return xxx_messageInfo_ImportedMessage.Size(m)
-}
-func (m *ImportedMessage) XXX_DiscardUnknown() {
-	xxx_messageInfo_ImportedMessage.DiscardUnknown(m)
-}
-
-var xxx_messageInfo_ImportedMessage proto.InternalMessageInfo
-
-type isImportedMessage_Union interface {
-	isImportedMessage_Union()
-}
-
-type ImportedMessage_State struct {
-	State int32 `protobuf:"varint,9,opt,name=state,oneof"`
-}
-
-func (*ImportedMessage_State) isImportedMessage_Union() {}
-
-func (m *ImportedMessage) GetUnion() isImportedMessage_Union {
-	if m != nil {
-		return m.Union
-	}
-	return nil
-}
-
-func (m *ImportedMessage) GetField() int64 {
-	if m != nil && m.Field != nil {
-		return *m.Field
-	}
-	return 0
-}
-
-func (m *ImportedMessage) GetLocalMsg() *ImportedMessage2 {
-	if m != nil {
-		return m.LocalMsg
-	}
-	return nil
-}
-
-func (m *ImportedMessage) GetForeignMsg() *imp3.ForeignImportedMessage {
-	if m != nil {
-		return m.ForeignMsg
-	}
-	return nil
-}
-
-func (m *ImportedMessage) GetEnumField() ImportedMessage_Owner {
-	if m != nil && m.EnumField != nil {
-		return *m.EnumField
-	}
-	return ImportedMessage_DAVE
-}
-
-func (m *ImportedMessage) GetState() int32 {
-	if x, ok := m.GetUnion().(*ImportedMessage_State); ok {
-		return x.State
-	}
-	return 0
-}
-
-func (m *ImportedMessage) GetName() []string {
-	if m != nil {
-		return m.Name
-	}
-	return nil
-}
-
-func (m *ImportedMessage) GetBoss() []ImportedMessage_Owner {
-	if m != nil {
-		return m.Boss
-	}
-	return nil
-}
-
-func (m *ImportedMessage) GetMemo() []*ImportedMessage2 {
-	if m != nil {
-		return m.Memo
-	}
-	return nil
-}
-
-func (m *ImportedMessage) GetMsgMap() map[string]*ImportedMessage2 {
-	if m != nil {
-		return m.MsgMap
-	}
-	return nil
-}
-
-// XXX_OneofFuncs is for the internal use of the proto package.
-func (*ImportedMessage) XXX_OneofFuncs() (func(msg proto.Message, b *proto.Buffer) error, func(msg proto.Message, tag, wire int, b *proto.Buffer) (bool, error), func(msg proto.Message) (n int), []interface{}) {
-	return _ImportedMessage_OneofMarshaler, _ImportedMessage_OneofUnmarshaler, _ImportedMessage_OneofSizer, []interface{}{
-		(*ImportedMessage_State)(nil),
-	}
-}
-
-func _ImportedMessage_OneofMarshaler(msg proto.Message, b *proto.Buffer) error {
-	m := msg.(*ImportedMessage)
-	// union
-	switch x := m.Union.(type) {
-	case *ImportedMessage_State:
-		b.EncodeVarint(9<<3 | proto.WireVarint)
-		b.EncodeVarint(uint64(x.State))
-	case nil:
-	default:
-		return fmt.Errorf("ImportedMessage.Union has unexpected type %T", x)
-	}
-	return nil
-}
-
-func _ImportedMessage_OneofUnmarshaler(msg proto.Message, tag, wire int, b *proto.Buffer) (bool, error) {
-	m := msg.(*ImportedMessage)
-	switch tag {
-	case 9: // union.state
-		if wire != proto.WireVarint {
-			return true, proto.ErrInternalBadWireType
-		}
-		x, err := b.DecodeVarint()
-		m.Union = &ImportedMessage_State{int32(x)}
-		return true, err
-	default:
-		return false, nil
-	}
-}
-
-func _ImportedMessage_OneofSizer(msg proto.Message) (n int) {
-	m := msg.(*ImportedMessage)
-	// union
-	switch x := m.Union.(type) {
-	case *ImportedMessage_State:
-		n += 1 // tag and wire
-		n += proto.SizeVarint(uint64(x.State))
-	case nil:
-	default:
-		panic(fmt.Sprintf("proto: unexpected type %T in oneof", x))
-	}
-	return n
-}
-
-type ImportedMessage2 struct {
-	XXX_NoUnkeyedLiteral struct{} `json:"-"`
-	XXX_unrecognized     []byte   `json:"-"`
-	XXX_sizecache        int32    `json:"-"`
-}
-
-func (m *ImportedMessage2) Reset()         { *m = ImportedMessage2{} }
-func (m *ImportedMessage2) String() string { return proto.CompactTextString(m) }
-func (*ImportedMessage2) ProtoMessage()    {}
-func (*ImportedMessage2) Descriptor() ([]byte, []int) {
-	return fileDescriptor_imp_6424de66809c2ae5, []int{1}
-}
-func (m *ImportedMessage2) XXX_Unmarshal(b []byte) error {
-	return xxx_messageInfo_ImportedMessage2.Unmarshal(m, b)
-}
-func (m *ImportedMessage2) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
-	return xxx_messageInfo_ImportedMessage2.Marshal(b, m, deterministic)
-}
-func (dst *ImportedMessage2) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_ImportedMessage2.Merge(dst, src)
-}
-func (m *ImportedMessage2) XXX_Size() int {
-	return xxx_messageInfo_ImportedMessage2.Size(m)
-}
-func (m *ImportedMessage2) XXX_DiscardUnknown() {
-	xxx_messageInfo_ImportedMessage2.DiscardUnknown(m)
-}
-
-var xxx_messageInfo_ImportedMessage2 proto.InternalMessageInfo
-
-type ImportedExtendable struct {
-	XXX_NoUnkeyedLiteral         struct{} `json:"-"`
-	proto.XXX_InternalExtensions `protobuf_messageset:"1" json:"-"`
-	XXX_unrecognized             []byte `json:"-"`
-	XXX_sizecache                int32  `json:"-"`
-}
-
-func (m *ImportedExtendable) Reset()         { *m = ImportedExtendable{} }
-func (m *ImportedExtendable) String() string { return proto.CompactTextString(m) }
-func (*ImportedExtendable) ProtoMessage()    {}
-func (*ImportedExtendable) Descriptor() ([]byte, []int) {
-	return fileDescriptor_imp_6424de66809c2ae5, []int{2}
-}
-
-func (m *ImportedExtendable) MarshalJSON() ([]byte, error) {
-	return proto.MarshalMessageSetJSON(&m.XXX_InternalExtensions)
-}
-func (m *ImportedExtendable) UnmarshalJSON(buf []byte) error {
-	return proto.UnmarshalMessageSetJSON(buf, &m.XXX_InternalExtensions)
-}
-
-var extRange_ImportedExtendable = []proto.ExtensionRange{
-	{Start: 100, End: 2147483646},
-}
-
-func (*ImportedExtendable) ExtensionRangeArray() []proto.ExtensionRange {
-	return extRange_ImportedExtendable
-}
-func (m *ImportedExtendable) XXX_Unmarshal(b []byte) error {
-	return xxx_messageInfo_ImportedExtendable.Unmarshal(m, b)
-}
-func (m *ImportedExtendable) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
-	return xxx_messageInfo_ImportedExtendable.Marshal(b, m, deterministic)
-}
-func (dst *ImportedExtendable) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_ImportedExtendable.Merge(dst, src)
-}
-func (m *ImportedExtendable) XXX_Size() int {
-	return xxx_messageInfo_ImportedExtendable.Size(m)
-}
-func (m *ImportedExtendable) XXX_DiscardUnknown() {
-	xxx_messageInfo_ImportedExtendable.DiscardUnknown(m)
-}
-
-var xxx_messageInfo_ImportedExtendable proto.InternalMessageInfo
-
-func init() {
-	proto.RegisterType((*ImportedMessage)(nil), "imp.ImportedMessage")
-	proto.RegisterMapType((map[string]*ImportedMessage2)(nil), "imp.ImportedMessage.MsgMapEntry")
-	proto.RegisterType((*ImportedMessage2)(nil), "imp.ImportedMessage2")
-	proto.RegisterType((*ImportedExtendable)(nil), "imp.ImportedExtendable")
-	proto.RegisterEnum("imp.ImportedMessage_Owner", ImportedMessage_Owner_name, ImportedMessage_Owner_value)
-}
-
-func init() { proto.RegisterFile("imp/imp.proto", fileDescriptor_imp_6424de66809c2ae5) }
-
-var fileDescriptor_imp_6424de66809c2ae5 = []byte{
-	// 427 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x84, 0x52, 0x4d, 0x6f, 0xd4, 0x30,
-	0x10, 0xad, 0xf3, 0xd1, 0x4d, 0x66, 0x05, 0x44, 0xe6, 0x43, 0xd1, 0xf6, 0x62, 0xe5, 0x14, 0x8a,
-	0x9a, 0x95, 0x82, 0x10, 0xb4, 0xe2, 0x42, 0xc5, 0x56, 0x54, 0x28, 0xa2, 0xca, 0x81, 0x43, 0x2f,
-	0x2b, 0xef, 0xc6, 0x6b, 0x22, 0x62, 0x3b, 0x8a, 0x1d, 0xa0, 0xff, 0x83, 0xff, 0x1b, 0x14, 0xa7,
-	0x20, 0xb4, 0x2a, 0xf4, 0x32, 0x7a, 0xf3, 0xfc, 0xde, 0xcc, 0xd8, 0x1e, 0x78, 0x50, 0x8b, 0x76,
-	0x59, 0x8b, 0x36, 0x6b, 0x3b, 0x65, 0x14, 0x76, 0x6b, 0xd1, 0x2e, 0x1e, 0xdf, 0x72, 0xb9, 0x0d,
-	0xd3, 0xc9, 0x1f, 0xf2, 0xa5, 0x0d, 0x13, 0x99, 0xfc, 0xf4, 0xe0, 0xd1, 0xa5, 0x68, 0x55, 0x67,
-	0x58, 0x55, 0x30, 0xad, 0x29, 0x67, 0xf8, 0x09, 0xf8, 0xbb, 0x9a, 0x35, 0x55, 0x8c, 0x88, 0x93,
-	0xba, 0xe5, 0x94, 0xe0, 0x1c, 0xc2, 0x46, 0x6d, 0x69, 0xb3, 0x16, 0x9a, 0xc7, 0x0e, 0x41, 0xe9,
-	0x3c, 0x7f, 0x9a, 0x8d, 0x7d, 0xf7, 0xec, 0x79, 0x19, 0x58, 0x5d, 0xa1, 0x39, 0x7e, 0x0b, 0xf3,
-	0x9d, 0xea, 0x58, 0xcd, 0xa5, 0x75, 0xb9, 0xd6, 0x75, 0x64, 0x5d, 0x17, 0x13, 0xbf, 0x67, 0x2e,
-	0xe1, 0x56, 0x3f, 0xba, 0x4f, 0x01, 0x98, 0xec, 0xc5, 0x7a, 0x1a, 0xc6, 0x23, 0x28, 0x7d, 0x98,
-	0x2f, 0xee, 0x6a, 0x99, 0x7d, 0xfa, 0x2e, 0x59, 0x57, 0x86, 0xa3, 0xfa, 0xc2, 0x0e, 0xfb, 0x0c,
-	0x7c, 0x6d, 0xa8, 0x61, 0x71, 0x48, 0x50, 0xea, 0x7f, 0x38, 0x28, 0xa7, 0x14, 0x63, 0xf0, 0x24,
-	0x15, 0x2c, 0xf6, 0x89, 0x9b, 0x86, 0xa5, 0xc5, 0x38, 0x03, 0x6f, 0xa3, 0xb4, 0x8e, 0x0f, 0x89,
-	0x7b, 0x4f, 0x03, 0xab, 0xc3, 0xcf, 0xc1, 0x13, 0x4c, 0xa8, 0x78, 0x46, 0xdc, 0x7f, 0xbf, 0x81,
-	0x95, 0xe0, 0x53, 0x98, 0x09, 0xcd, 0xd7, 0x82, 0xb6, 0x71, 0x60, 0xd5, 0xe4, 0xce, 0xea, 0x85,
-	0xe6, 0x05, 0x6d, 0x57, 0xd2, 0x74, 0x37, 0xe5, 0xa1, 0xb0, 0xc9, 0xe2, 0x0a, 0xe6, 0x7f, 0xd1,
-	0x38, 0x02, 0xf7, 0x2b, 0xbb, 0x89, 0x11, 0x41, 0x69, 0x58, 0x8e, 0x10, 0xbf, 0x00, 0xff, 0x1b,
-	0x6d, 0x7a, 0xf6, 0xff, 0xbf, 0x98, 0x34, 0x67, 0xce, 0x1b, 0x94, 0x1c, 0x81, 0x6f, 0xaf, 0x81,
-	0x03, 0xf0, 0xde, 0xbf, 0xfb, 0xbc, 0x8a, 0xd0, 0x88, 0x8a, 0xcb, 0x8f, 0xab, 0xc8, 0x39, 0xf6,
-	0x82, 0xeb, 0x88, 0x9d, 0xcf, 0xc0, 0xef, 0x65, 0xad, 0x64, 0x82, 0x21, 0xda, 0x2f, 0x95, 0x24,
-	0x80, 0x7f, 0x73, 0xab, 0x1f, 0x86, 0xc9, 0x8a, 0x6e, 0x1a, 0x76, 0x1c, 0x04, 0x55, 0x34, 0x0c,
-	0xc3, 0x30, 0x3b, 0x73, 0x02, 0x74, 0xfe, 0xfa, 0xfa, 0x15, 0xaf, 0xcd, 0x97, 0x7e, 0x93, 0x6d,
-	0x95, 0x58, 0x72, 0xd5, 0x50, 0xc9, 0x97, 0x76, 0xd3, 0x36, 0xfd, 0x6e, 0x02, 0xdb, 0x13, 0xce,
-	0xe4, 0x09, 0x57, 0x4b, 0xc3, 0xb4, 0xa9, 0xa8, 0xa1, 0xe3, 0x3a, 0x5e, 0x1d, 0xfc, 0x0a, 0x00,
-	0x00, 0xff, 0xff, 0xe7, 0x7a, 0x0f, 0x3a, 0xc8, 0x02, 0x00, 0x00,
-}
diff --git a/protoc-gen-go/testdata/imp/imp.proto b/protoc-gen-go/testdata/imp/imp.proto
deleted file mode 100644
index 43f88baced..0000000000
--- a/protoc-gen-go/testdata/imp/imp.proto
+++ /dev/null
@@ -1,72 +0,0 @@
-// Go support for Protocol Buffers - Google's data interchange format
-//
-// Copyright 2010 The Go Authors.  All rights reserved.
-// https://github.com/golang/protobuf
-//
-// 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.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// 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
-// OWNER 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.
-
-syntax = "proto2";
-
-package imp;
-
-option go_package = "github.com/golang/protobuf/protoc-gen-go/testdata/imp";
-
-import public "imp/imp2/imp2.proto";
-import "imp/imp3/imp3.proto";
-
-message ImportedMessage {
-  required int64 field = 1;
-
-  // The forwarded getters for these fields are fiddly to get right.
-  optional ImportedMessage2 local_msg = 2;
-  optional ForeignImportedMessage foreign_msg = 3;  // in imp3.proto
-  optional Owner enum_field = 4;
-  oneof union {
-    int32 state = 9;
-  }
-
-  repeated string name = 5;
-  repeated Owner boss = 6;
-  repeated ImportedMessage2 memo = 7;
-
-  map<string, ImportedMessage2> msg_map = 8;
-
-  enum Owner {
-    DAVE = 1;
-    MIKE = 2;
-  }
-
-  extensions 90 to 100;
-}
-
-message ImportedMessage2 {
-}
-
-message ImportedExtendable {
-  option message_set_wire_format = true;
-  extensions 100 to max;
-}
diff --git a/protoc-gen-go/testdata/imp/imp2/imp2-enum.pb.go b/protoc-gen-go/testdata/imp/imp2/imp2-enum.pb.go
deleted file mode 100644
index 65f53bb508..0000000000
--- a/protoc-gen-go/testdata/imp/imp2/imp2-enum.pb.go
+++ /dev/null
@@ -1,102 +0,0 @@
-// Code generated by protoc-gen-go. DO NOT EDIT.
-// source: imp/imp2/imp2-enum.proto
-
-package imp2 // import "github.com/golang/protobuf/protoc-gen-go/testdata/imp/imp2"
-
-import proto "github.com/golang/protobuf/proto"
-import fmt "fmt"
-import math "math"
-
-// Reference imports to suppress errors if they are not otherwise used.
-var _ = proto.Marshal
-var _ = fmt.Errorf
-var _ = math.Inf
-
-// This is a compile-time assertion to ensure that this generated file
-// is compatible with the proto package it is being compiled against.
-// A compilation error at this line likely means your copy of the
-// proto package needs to be updated.
-const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
-
-type EnumPB_Type int32
-
-const (
-	EnumPB_TYPE_1 EnumPB_Type = 0
-)
-
-var EnumPB_Type_name = map[int32]string{
-	0: "TYPE_1",
-}
-var EnumPB_Type_value = map[string]int32{
-	"TYPE_1": 0,
-}
-
-func (x EnumPB_Type) Enum() *EnumPB_Type {
-	p := new(EnumPB_Type)
-	*p = x
-	return p
-}
-func (x EnumPB_Type) String() string {
-	return proto.EnumName(EnumPB_Type_name, int32(x))
-}
-func (x *EnumPB_Type) UnmarshalJSON(data []byte) error {
-	value, err := proto.UnmarshalJSONEnum(EnumPB_Type_value, data, "EnumPB_Type")
-	if err != nil {
-		return err
-	}
-	*x = EnumPB_Type(value)
-	return nil
-}
-func (EnumPB_Type) EnumDescriptor() ([]byte, []int) {
-	return fileDescriptor_imp2_enum_1cca8279ac3cbb94, []int{0, 0}
-}
-
-type EnumPB struct {
-	XXX_NoUnkeyedLiteral struct{} `json:"-"`
-	XXX_unrecognized     []byte   `json:"-"`
-	XXX_sizecache        int32    `json:"-"`
-}
-
-func (m *EnumPB) Reset()         { *m = EnumPB{} }
-func (m *EnumPB) String() string { return proto.CompactTextString(m) }
-func (*EnumPB) ProtoMessage()    {}
-func (*EnumPB) Descriptor() ([]byte, []int) {
-	return fileDescriptor_imp2_enum_1cca8279ac3cbb94, []int{0}
-}
-func (m *EnumPB) XXX_Unmarshal(b []byte) error {
-	return xxx_messageInfo_EnumPB.Unmarshal(m, b)
-}
-func (m *EnumPB) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
-	return xxx_messageInfo_EnumPB.Marshal(b, m, deterministic)
-}
-func (dst *EnumPB) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_EnumPB.Merge(dst, src)
-}
-func (m *EnumPB) XXX_Size() int {
-	return xxx_messageInfo_EnumPB.Size(m)
-}
-func (m *EnumPB) XXX_DiscardUnknown() {
-	xxx_messageInfo_EnumPB.DiscardUnknown(m)
-}
-
-var xxx_messageInfo_EnumPB proto.InternalMessageInfo
-
-func init() {
-	proto.RegisterType((*EnumPB)(nil), "imp.EnumPB")
-	proto.RegisterEnum("imp.EnumPB_Type", EnumPB_Type_name, EnumPB_Type_value)
-}
-
-func init() { proto.RegisterFile("imp/imp2/imp2-enum.proto", fileDescriptor_imp2_enum_1cca8279ac3cbb94) }
-
-var fileDescriptor_imp2_enum_1cca8279ac3cbb94 = []byte{
-	// 131 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x92, 0xc8, 0xcc, 0x2d, 0xd0,
-	0xcf, 0xcc, 0x2d, 0x30, 0x02, 0x13, 0xba, 0xa9, 0x79, 0xa5, 0xb9, 0x7a, 0x05, 0x45, 0xf9, 0x25,
-	0xf9, 0x42, 0xcc, 0x99, 0xb9, 0x05, 0x4a, 0x32, 0x5c, 0x6c, 0xae, 0x79, 0xa5, 0xb9, 0x01, 0x4e,
-	0x4a, 0x42, 0x5c, 0x2c, 0x21, 0x95, 0x05, 0xa9, 0x42, 0x5c, 0x5c, 0x6c, 0x21, 0x91, 0x01, 0xae,
-	0xf1, 0x86, 0x02, 0x0c, 0x4e, 0x36, 0x51, 0x56, 0xe9, 0x99, 0x25, 0x19, 0xa5, 0x49, 0x7a, 0xc9,
-	0xf9, 0xb9, 0xfa, 0xe9, 0xf9, 0x39, 0x89, 0x79, 0xe9, 0xfa, 0x60, 0xdd, 0x49, 0xa5, 0x69, 0x10,
-	0x46, 0xb2, 0x6e, 0x7a, 0x6a, 0x9e, 0x6e, 0x7a, 0xbe, 0x7e, 0x49, 0x6a, 0x71, 0x49, 0x4a, 0x62,
-	0x49, 0xa2, 0x3e, 0xcc, 0x42, 0x40, 0x00, 0x00, 0x00, 0xff, 0xff, 0xc6, 0x64, 0x9c, 0xa4, 0x7b,
-	0x00, 0x00, 0x00,
-}
diff --git a/protoc-gen-go/testdata/imp/imp2/imp2.pb.go b/protoc-gen-go/testdata/imp/imp2/imp2.pb.go
deleted file mode 100644
index ecdcf6d597..0000000000
--- a/protoc-gen-go/testdata/imp/imp2/imp2.pb.go
+++ /dev/null
@@ -1,167 +0,0 @@
-// Code generated by protoc-gen-go. DO NOT EDIT.
-// source: imp/imp2/imp2.proto
-
-package imp2 // import "github.com/golang/protobuf/protoc-gen-go/testdata/imp/imp2"
-
-import proto "github.com/golang/protobuf/proto"
-import fmt "fmt"
-import math "math"
-
-// Reference imports to suppress errors if they are not otherwise used.
-var _ = proto.Marshal
-var _ = fmt.Errorf
-var _ = math.Inf
-
-// This is a compile-time assertion to ensure that this generated file
-// is compatible with the proto package it is being compiled against.
-// A compilation error at this line likely means your copy of the
-// proto package needs to be updated.
-const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
-
-type PubliclyImportedEnum int32
-
-const (
-	PubliclyImportedEnum_GLASSES PubliclyImportedEnum = 1
-	PubliclyImportedEnum_HAIR    PubliclyImportedEnum = 2
-)
-
-var PubliclyImportedEnum_name = map[int32]string{
-	1: "GLASSES",
-	2: "HAIR",
-}
-var PubliclyImportedEnum_value = map[string]int32{
-	"GLASSES": 1,
-	"HAIR":    2,
-}
-
-func (x PubliclyImportedEnum) Enum() *PubliclyImportedEnum {
-	p := new(PubliclyImportedEnum)
-	*p = x
-	return p
-}
-func (x PubliclyImportedEnum) String() string {
-	return proto.EnumName(PubliclyImportedEnum_name, int32(x))
-}
-func (x *PubliclyImportedEnum) UnmarshalJSON(data []byte) error {
-	value, err := proto.UnmarshalJSONEnum(PubliclyImportedEnum_value, data, "PubliclyImportedEnum")
-	if err != nil {
-		return err
-	}
-	*x = PubliclyImportedEnum(value)
-	return nil
-}
-func (PubliclyImportedEnum) EnumDescriptor() ([]byte, []int) {
-	return fileDescriptor_imp2_8c527bbde1f96503, []int{0}
-}
-
-type PubliclyImportedMessage struct {
-	Field *int64 `protobuf:"varint,1,opt,name=field" json:"field,omitempty"`
-	// Field using a type in the same Go package, but a different source file.
-	Field2               *EnumPB_Type `protobuf:"varint,2,opt,name=field2,enum=imp.EnumPB_Type" json:"field2,omitempty"`
-	XXX_NoUnkeyedLiteral struct{}     `json:"-"`
-	XXX_unrecognized     []byte       `json:"-"`
-	XXX_sizecache        int32        `json:"-"`
-}
-
-func (m *PubliclyImportedMessage) Reset()         { *m = PubliclyImportedMessage{} }
-func (m *PubliclyImportedMessage) String() string { return proto.CompactTextString(m) }
-func (*PubliclyImportedMessage) ProtoMessage()    {}
-func (*PubliclyImportedMessage) Descriptor() ([]byte, []int) {
-	return fileDescriptor_imp2_8c527bbde1f96503, []int{0}
-}
-func (m *PubliclyImportedMessage) XXX_Unmarshal(b []byte) error {
-	return xxx_messageInfo_PubliclyImportedMessage.Unmarshal(m, b)
-}
-func (m *PubliclyImportedMessage) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
-	return xxx_messageInfo_PubliclyImportedMessage.Marshal(b, m, deterministic)
-}
-func (dst *PubliclyImportedMessage) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_PubliclyImportedMessage.Merge(dst, src)
-}
-func (m *PubliclyImportedMessage) XXX_Size() int {
-	return xxx_messageInfo_PubliclyImportedMessage.Size(m)
-}
-func (m *PubliclyImportedMessage) XXX_DiscardUnknown() {
-	xxx_messageInfo_PubliclyImportedMessage.DiscardUnknown(m)
-}
-
-var xxx_messageInfo_PubliclyImportedMessage proto.InternalMessageInfo
-
-func (m *PubliclyImportedMessage) GetField() int64 {
-	if m != nil && m.Field != nil {
-		return *m.Field
-	}
-	return 0
-}
-
-func (m *PubliclyImportedMessage) GetField2() EnumPB_Type {
-	if m != nil && m.Field2 != nil {
-		return *m.Field2
-	}
-	return EnumPB_TYPE_1
-}
-
-type PubliclyImportedMessage2 struct {
-	Field                *PubliclyImportedMessage `protobuf:"bytes,1,opt,name=field" json:"field,omitempty"`
-	XXX_NoUnkeyedLiteral struct{}                 `json:"-"`
-	XXX_unrecognized     []byte                   `json:"-"`
-	XXX_sizecache        int32                    `json:"-"`
-}
-
-func (m *PubliclyImportedMessage2) Reset()         { *m = PubliclyImportedMessage2{} }
-func (m *PubliclyImportedMessage2) String() string { return proto.CompactTextString(m) }
-func (*PubliclyImportedMessage2) ProtoMessage()    {}
-func (*PubliclyImportedMessage2) Descriptor() ([]byte, []int) {
-	return fileDescriptor_imp2_8c527bbde1f96503, []int{1}
-}
-func (m *PubliclyImportedMessage2) XXX_Unmarshal(b []byte) error {
-	return xxx_messageInfo_PubliclyImportedMessage2.Unmarshal(m, b)
-}
-func (m *PubliclyImportedMessage2) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
-	return xxx_messageInfo_PubliclyImportedMessage2.Marshal(b, m, deterministic)
-}
-func (dst *PubliclyImportedMessage2) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_PubliclyImportedMessage2.Merge(dst, src)
-}
-func (m *PubliclyImportedMessage2) XXX_Size() int {
-	return xxx_messageInfo_PubliclyImportedMessage2.Size(m)
-}
-func (m *PubliclyImportedMessage2) XXX_DiscardUnknown() {
-	xxx_messageInfo_PubliclyImportedMessage2.DiscardUnknown(m)
-}
-
-var xxx_messageInfo_PubliclyImportedMessage2 proto.InternalMessageInfo
-
-func (m *PubliclyImportedMessage2) GetField() *PubliclyImportedMessage {
-	if m != nil {
-		return m.Field
-	}
-	return nil
-}
-
-func init() {
-	proto.RegisterType((*PubliclyImportedMessage)(nil), "imp.PubliclyImportedMessage")
-	proto.RegisterType((*PubliclyImportedMessage2)(nil), "imp.PubliclyImportedMessage2")
-	proto.RegisterEnum("imp.PubliclyImportedEnum", PubliclyImportedEnum_name, PubliclyImportedEnum_value)
-}
-
-func init() { proto.RegisterFile("imp/imp2/imp2.proto", fileDescriptor_imp2_8c527bbde1f96503) }
-
-var fileDescriptor_imp2_8c527bbde1f96503 = []byte{
-	// 238 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x12, 0xce, 0xcc, 0x2d, 0xd0,
-	0xcf, 0xcc, 0x2d, 0x30, 0x02, 0x13, 0x7a, 0x05, 0x45, 0xf9, 0x25, 0xf9, 0x42, 0xcc, 0x99, 0xb9,
-	0x05, 0x52, 0x12, 0x28, 0x32, 0xba, 0xa9, 0x79, 0xa5, 0xb9, 0x10, 0x69, 0xa5, 0x48, 0x2e, 0xf1,
-	0x80, 0xd2, 0xa4, 0x9c, 0xcc, 0xe4, 0x9c, 0x4a, 0xcf, 0xdc, 0x82, 0xfc, 0xa2, 0x92, 0xd4, 0x14,
-	0xdf, 0xd4, 0xe2, 0xe2, 0xc4, 0xf4, 0x54, 0x21, 0x11, 0x2e, 0xd6, 0xb4, 0xcc, 0xd4, 0x9c, 0x14,
-	0x09, 0x46, 0x05, 0x46, 0x0d, 0xe6, 0x20, 0x08, 0x47, 0x48, 0x83, 0x8b, 0x0d, 0xcc, 0x30, 0x92,
-	0x60, 0x52, 0x60, 0xd4, 0xe0, 0x33, 0x12, 0xd0, 0xcb, 0xcc, 0x2d, 0xd0, 0x73, 0xcd, 0x2b, 0xcd,
-	0x0d, 0x70, 0xd2, 0x0b, 0xa9, 0x2c, 0x48, 0x0d, 0x82, 0xca, 0x2b, 0xf9, 0x71, 0x49, 0xe0, 0x30,
-	0xda, 0x48, 0xc8, 0x08, 0xd9, 0x6c, 0x6e, 0x23, 0x19, 0xb0, 0x21, 0x38, 0x54, 0x43, 0x6d, 0xd6,
-	0xd2, 0xe5, 0x12, 0x41, 0x57, 0x01, 0xb2, 0x56, 0x88, 0x9b, 0x8b, 0xdd, 0xdd, 0xc7, 0x31, 0x38,
-	0xd8, 0x35, 0x58, 0x80, 0x51, 0x88, 0x83, 0x8b, 0xc5, 0xc3, 0xd1, 0x33, 0x48, 0x80, 0xc9, 0xc9,
-	0x26, 0xca, 0x2a, 0x3d, 0xb3, 0x24, 0xa3, 0x34, 0x49, 0x2f, 0x39, 0x3f, 0x57, 0x3f, 0x3d, 0x3f,
-	0x27, 0x31, 0x2f, 0x5d, 0x1f, 0xec, 0xe9, 0xa4, 0xd2, 0x34, 0x08, 0x23, 0x59, 0x37, 0x3d, 0x35,
-	0x4f, 0x37, 0x3d, 0x5f, 0xbf, 0x24, 0xb5, 0xb8, 0x24, 0x25, 0xb1, 0x24, 0x51, 0x1f, 0x16, 0x4e,
-	0x80, 0x00, 0x00, 0x00, 0xff, 0xff, 0xdf, 0xf8, 0xc4, 0xf4, 0x4c, 0x01, 0x00, 0x00,
-}
diff --git a/protoc-gen-go/testdata/imp/imp3/imp3.pb.go b/protoc-gen-go/testdata/imp/imp3/imp3.pb.go
deleted file mode 100644
index 1d2833939f..0000000000
--- a/protoc-gen-go/testdata/imp/imp3/imp3.pb.go
+++ /dev/null
@@ -1,76 +0,0 @@
-// Code generated by protoc-gen-go. DO NOT EDIT.
-// source: imp/imp3/imp3.proto
-
-package imp3 // import "github.com/golang/protobuf/protoc-gen-go/testdata/imp/imp3"
-
-import proto "github.com/golang/protobuf/proto"
-import fmt "fmt"
-import math "math"
-
-// Reference imports to suppress errors if they are not otherwise used.
-var _ = proto.Marshal
-var _ = fmt.Errorf
-var _ = math.Inf
-
-// This is a compile-time assertion to ensure that this generated file
-// is compatible with the proto package it is being compiled against.
-// A compilation error at this line likely means your copy of the
-// proto package needs to be updated.
-const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
-
-type ForeignImportedMessage struct {
-	Tuber                *string  `protobuf:"bytes,1,opt,name=tuber" json:"tuber,omitempty"`
-	XXX_NoUnkeyedLiteral struct{} `json:"-"`
-	XXX_unrecognized     []byte   `json:"-"`
-	XXX_sizecache        int32    `json:"-"`
-}
-
-func (m *ForeignImportedMessage) Reset()         { *m = ForeignImportedMessage{} }
-func (m *ForeignImportedMessage) String() string { return proto.CompactTextString(m) }
-func (*ForeignImportedMessage) ProtoMessage()    {}
-func (*ForeignImportedMessage) Descriptor() ([]byte, []int) {
-	return fileDescriptor_imp3_4aae87d6f1c23d12, []int{0}
-}
-func (m *ForeignImportedMessage) XXX_Unmarshal(b []byte) error {
-	return xxx_messageInfo_ForeignImportedMessage.Unmarshal(m, b)
-}
-func (m *ForeignImportedMessage) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
-	return xxx_messageInfo_ForeignImportedMessage.Marshal(b, m, deterministic)
-}
-func (dst *ForeignImportedMessage) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_ForeignImportedMessage.Merge(dst, src)
-}
-func (m *ForeignImportedMessage) XXX_Size() int {
-	return xxx_messageInfo_ForeignImportedMessage.Size(m)
-}
-func (m *ForeignImportedMessage) XXX_DiscardUnknown() {
-	xxx_messageInfo_ForeignImportedMessage.DiscardUnknown(m)
-}
-
-var xxx_messageInfo_ForeignImportedMessage proto.InternalMessageInfo
-
-func (m *ForeignImportedMessage) GetTuber() string {
-	if m != nil && m.Tuber != nil {
-		return *m.Tuber
-	}
-	return ""
-}
-
-func init() {
-	proto.RegisterType((*ForeignImportedMessage)(nil), "imp.ForeignImportedMessage")
-}
-
-func init() { proto.RegisterFile("imp/imp3/imp3.proto", fileDescriptor_imp3_4aae87d6f1c23d12) }
-
-var fileDescriptor_imp3_4aae87d6f1c23d12 = []byte{
-	// 139 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x12, 0xce, 0xcc, 0x2d, 0xd0,
-	0xcf, 0xcc, 0x2d, 0x30, 0x06, 0x13, 0x7a, 0x05, 0x45, 0xf9, 0x25, 0xf9, 0x42, 0xcc, 0x99, 0xb9,
-	0x05, 0x4a, 0x7a, 0x5c, 0x62, 0x6e, 0xf9, 0x45, 0xa9, 0x99, 0xe9, 0x79, 0x9e, 0xb9, 0x05, 0xf9,
-	0x45, 0x25, 0xa9, 0x29, 0xbe, 0xa9, 0xc5, 0xc5, 0x89, 0xe9, 0xa9, 0x42, 0x22, 0x5c, 0xac, 0x25,
-	0xa5, 0x49, 0xa9, 0x45, 0x12, 0x8c, 0x0a, 0x8c, 0x1a, 0x9c, 0x41, 0x10, 0x8e, 0x93, 0x4d, 0x94,
-	0x55, 0x7a, 0x66, 0x49, 0x46, 0x69, 0x92, 0x5e, 0x72, 0x7e, 0xae, 0x7e, 0x7a, 0x7e, 0x4e, 0x62,
-	0x5e, 0xba, 0x3e, 0xd8, 0xbc, 0xa4, 0xd2, 0x34, 0x08, 0x23, 0x59, 0x37, 0x3d, 0x35, 0x4f, 0x37,
-	0x3d, 0x5f, 0xbf, 0x24, 0xb5, 0xb8, 0x24, 0x25, 0xb1, 0x24, 0x51, 0x1f, 0x66, 0x3b, 0x20, 0x00,
-	0x00, 0xff, 0xff, 0xda, 0xb9, 0x43, 0xe2, 0x88, 0x00, 0x00, 0x00,
-}
diff --git a/protoc-gen-go/testdata/import_public/a.pb.go b/protoc-gen-go/testdata/import_public/a.pb.go
new file mode 100644
index 0000000000..5b780fd5cf
--- /dev/null
+++ b/protoc-gen-go/testdata/import_public/a.pb.go
@@ -0,0 +1,110 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// source: import_public/a.proto
+
+package import_public // import "github.com/golang/protobuf/protoc-gen-go/testdata/import_public"
+
+import proto "github.com/golang/protobuf/proto"
+import fmt "fmt"
+import math "math"
+import sub "github.com/golang/protobuf/protoc-gen-go/testdata/import_public/sub"
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+
+// M from public import import_public/sub/a.proto
+type M = sub.M
+
+// E from public import import_public/sub/a.proto
+type E = sub.E
+
+var E_name = sub.E_name
+var E_value = sub.E_value
+
+const E_ZERO = E(sub.E_ZERO)
+
+// Ignoring public import of Local from import_public/b.proto
+
+type Public struct {
+	M                    *sub.M   `protobuf:"bytes,1,opt,name=m" json:"m,omitempty"`
+	E                    sub.E    `protobuf:"varint,2,opt,name=e,enum=goproto.test.import_public.sub.E" json:"e,omitempty"`
+	Local                *Local   `protobuf:"bytes,3,opt,name=local" json:"local,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *Public) Reset()         { *m = Public{} }
+func (m *Public) String() string { return proto.CompactTextString(m) }
+func (*Public) ProtoMessage()    {}
+func (*Public) Descriptor() ([]byte, []int) {
+	return fileDescriptor_a_c0314c022b7c17d8, []int{0}
+}
+func (m *Public) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_Public.Unmarshal(m, b)
+}
+func (m *Public) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_Public.Marshal(b, m, deterministic)
+}
+func (dst *Public) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Public.Merge(dst, src)
+}
+func (m *Public) XXX_Size() int {
+	return xxx_messageInfo_Public.Size(m)
+}
+func (m *Public) XXX_DiscardUnknown() {
+	xxx_messageInfo_Public.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_Public proto.InternalMessageInfo
+
+func (m *Public) GetM() *sub.M {
+	if m != nil {
+		return m.M
+	}
+	return nil
+}
+
+func (m *Public) GetE() sub.E {
+	if m != nil {
+		return m.E
+	}
+	return sub.E_ZERO
+}
+
+func (m *Public) GetLocal() *Local {
+	if m != nil {
+		return m.Local
+	}
+	return nil
+}
+
+func init() {
+	proto.RegisterType((*Public)(nil), "goproto.test.import_public.Public")
+}
+
+func init() { proto.RegisterFile("import_public/a.proto", fileDescriptor_a_c0314c022b7c17d8) }
+
+var fileDescriptor_a_c0314c022b7c17d8 = []byte{
+	// 200 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x12, 0xcd, 0xcc, 0x2d, 0xc8,
+	0x2f, 0x2a, 0x89, 0x2f, 0x28, 0x4d, 0xca, 0xc9, 0x4c, 0xd6, 0x4f, 0xd4, 0x2b, 0x28, 0xca, 0x2f,
+	0xc9, 0x17, 0x92, 0x4a, 0xcf, 0x07, 0x33, 0xf4, 0x4a, 0x52, 0x8b, 0x4b, 0xf4, 0x50, 0xd4, 0x48,
+	0x49, 0xa2, 0x6a, 0x29, 0x2e, 0x4d, 0x82, 0x69, 0x93, 0x42, 0x33, 0x2d, 0x09, 0x22, 0xac, 0xb4,
+	0x98, 0x91, 0x8b, 0x2d, 0x00, 0x2c, 0x24, 0xa4, 0xcf, 0xc5, 0x98, 0x2b, 0xc1, 0xa8, 0xc0, 0xa8,
+	0xc1, 0x6d, 0xa4, 0xa8, 0x87, 0xdb, 0x12, 0xbd, 0xe2, 0xd2, 0x24, 0x3d, 0xdf, 0x20, 0xc6, 0x5c,
+	0x90, 0x86, 0x54, 0x09, 0x26, 0x05, 0x46, 0x0d, 0x3e, 0xc2, 0x1a, 0x5c, 0x83, 0x18, 0x53, 0x85,
+	0xcc, 0xb9, 0x58, 0x73, 0xf2, 0x93, 0x13, 0x73, 0x24, 0x98, 0x09, 0xdb, 0xe2, 0x03, 0x52, 0x18,
+	0x04, 0x51, 0xef, 0xe4, 0x18, 0x65, 0x9f, 0x9e, 0x59, 0x92, 0x51, 0x9a, 0xa4, 0x97, 0x9c, 0x9f,
+	0xab, 0x9f, 0x9e, 0x9f, 0x93, 0x98, 0x97, 0xae, 0x0f, 0xd6, 0x9a, 0x54, 0x9a, 0x06, 0x61, 0x24,
+	0xeb, 0xa6, 0xa7, 0xe6, 0xe9, 0xa6, 0xe7, 0xeb, 0x83, 0xcc, 0x4a, 0x49, 0x2c, 0x49, 0xd4, 0x47,
+	0x31, 0x2f, 0x80, 0x21, 0x80, 0x31, 0x89, 0x0d, 0xac, 0xd2, 0x18, 0x10, 0x00, 0x00, 0xff, 0xff,
+	0x70, 0xc5, 0xc3, 0x79, 0x5a, 0x01, 0x00, 0x00,
+}
diff --git a/protoc-gen-go/testdata/imp/imp2/imp2.proto b/protoc-gen-go/testdata/import_public/a.proto
similarity index 78%
rename from protoc-gen-go/testdata/imp/imp2/imp2.proto
rename to protoc-gen-go/testdata/import_public/a.proto
index 6e709f516c..957ad89711 100644
--- a/protoc-gen-go/testdata/imp/imp2/imp2.proto
+++ b/protoc-gen-go/testdata/import_public/a.proto
@@ -1,6 +1,6 @@
 // Go support for Protocol Buffers - Google's data interchange format
 //
-// Copyright 2011 The Go Authors.  All rights reserved.
+// Copyright 2018 The Go Authors.  All rights reserved.
 // https://github.com/golang/protobuf
 //
 // Redistribution and use in source and binary forms, with or without
@@ -29,26 +29,17 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-syntax = "proto2";
+syntax = "proto3";
 
-package imp;
+package goproto.test.import_public;
 
-option go_package = "github.com/golang/protobuf/protoc-gen-go/testdata/imp/imp2";
+option go_package = "github.com/golang/protobuf/protoc-gen-go/testdata/import_public";
 
-import "imp/imp2/imp2-enum.proto";
+import public "import_public/sub/a.proto"; // Different Go package.
+import public "import_public/b.proto";     // Same Go package.
 
-message PubliclyImportedMessage {
-  optional int64 field = 1;
-
-  // Field using a type in the same Go package, but a different source file.
-  optional imp.EnumPB.Type field2 = 2;
-}
-
-message PubliclyImportedMessage2 {
-  optional PubliclyImportedMessage field = 1;
-}
-
-enum PubliclyImportedEnum {
-  GLASSES = 1;
-  HAIR = 2;
+message Public {
+  goproto.test.import_public.sub.M m = 1;
+  goproto.test.import_public.sub.E e = 2;
+  Local local = 3;
 }
diff --git a/protoc-gen-go/testdata/import_public/b.pb.go b/protoc-gen-go/testdata/import_public/b.pb.go
new file mode 100644
index 0000000000..427aa4f32d
--- /dev/null
+++ b/protoc-gen-go/testdata/import_public/b.pb.go
@@ -0,0 +1,87 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// source: import_public/b.proto
+
+package import_public // import "github.com/golang/protobuf/protoc-gen-go/testdata/import_public"
+
+import proto "github.com/golang/protobuf/proto"
+import fmt "fmt"
+import math "math"
+import sub "github.com/golang/protobuf/protoc-gen-go/testdata/import_public/sub"
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+
+type Local struct {
+	M                    *sub.M   `protobuf:"bytes,1,opt,name=m" json:"m,omitempty"`
+	E                    sub.E    `protobuf:"varint,2,opt,name=e,enum=goproto.test.import_public.sub.E" json:"e,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *Local) Reset()         { *m = Local{} }
+func (m *Local) String() string { return proto.CompactTextString(m) }
+func (*Local) ProtoMessage()    {}
+func (*Local) Descriptor() ([]byte, []int) {
+	return fileDescriptor_b_7f20a805fad67bd0, []int{0}
+}
+func (m *Local) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_Local.Unmarshal(m, b)
+}
+func (m *Local) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_Local.Marshal(b, m, deterministic)
+}
+func (dst *Local) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Local.Merge(dst, src)
+}
+func (m *Local) XXX_Size() int {
+	return xxx_messageInfo_Local.Size(m)
+}
+func (m *Local) XXX_DiscardUnknown() {
+	xxx_messageInfo_Local.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_Local proto.InternalMessageInfo
+
+func (m *Local) GetM() *sub.M {
+	if m != nil {
+		return m.M
+	}
+	return nil
+}
+
+func (m *Local) GetE() sub.E {
+	if m != nil {
+		return m.E
+	}
+	return sub.E_ZERO
+}
+
+func init() {
+	proto.RegisterType((*Local)(nil), "goproto.test.import_public.Local")
+}
+
+func init() { proto.RegisterFile("import_public/b.proto", fileDescriptor_b_7f20a805fad67bd0) }
+
+var fileDescriptor_b_7f20a805fad67bd0 = []byte{
+	// 174 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x12, 0xcd, 0xcc, 0x2d, 0xc8,
+	0x2f, 0x2a, 0x89, 0x2f, 0x28, 0x4d, 0xca, 0xc9, 0x4c, 0xd6, 0x4f, 0xd2, 0x2b, 0x28, 0xca, 0x2f,
+	0xc9, 0x17, 0x92, 0x4a, 0xcf, 0x07, 0x33, 0xf4, 0x4a, 0x52, 0x8b, 0x4b, 0xf4, 0x50, 0xd4, 0x48,
+	0x49, 0xa2, 0x6a, 0x29, 0x2e, 0x4d, 0xd2, 0x4f, 0x84, 0x68, 0x53, 0xca, 0xe4, 0x62, 0xf5, 0xc9,
+	0x4f, 0x4e, 0xcc, 0x11, 0xd2, 0xe7, 0x62, 0xcc, 0x95, 0x60, 0x54, 0x60, 0xd4, 0xe0, 0x36, 0x52,
+	0xd4, 0xc3, 0x6d, 0x96, 0x5e, 0x71, 0x69, 0x92, 0x9e, 0x6f, 0x10, 0x63, 0x2e, 0x48, 0x43, 0xaa,
+	0x04, 0x93, 0x02, 0xa3, 0x06, 0x1f, 0x61, 0x0d, 0xae, 0x41, 0x8c, 0xa9, 0x4e, 0x8e, 0x51, 0xf6,
+	0xe9, 0x99, 0x25, 0x19, 0xa5, 0x49, 0x7a, 0xc9, 0xf9, 0xb9, 0xfa, 0xe9, 0xf9, 0x39, 0x89, 0x79,
+	0xe9, 0xfa, 0x60, 0x6d, 0x49, 0xa5, 0x69, 0x10, 0x46, 0xb2, 0x6e, 0x7a, 0x6a, 0x9e, 0x6e, 0x7a,
+	0xbe, 0x3e, 0xc8, 0x9c, 0x94, 0xc4, 0x92, 0x44, 0x7d, 0x14, 0xb3, 0x92, 0xd8, 0xc0, 0xaa, 0x8c,
+	0x01, 0x01, 0x00, 0x00, 0xff, 0xff, 0xd6, 0x2b, 0x5f, 0x8e, 0x04, 0x01, 0x00, 0x00,
+}
diff --git a/protoc-gen-go/testdata/imp/imp3/imp3.proto b/protoc-gen-go/testdata/import_public/b.proto
similarity index 86%
rename from protoc-gen-go/testdata/imp/imp3/imp3.proto
rename to protoc-gen-go/testdata/import_public/b.proto
index a322a74ee3..1dbca3e496 100644
--- a/protoc-gen-go/testdata/imp/imp3/imp3.proto
+++ b/protoc-gen-go/testdata/import_public/b.proto
@@ -1,6 +1,6 @@
 // Go support for Protocol Buffers - Google's data interchange format
 //
-// Copyright 2012 The Go Authors.  All rights reserved.
+// Copyright 2018 The Go Authors.  All rights reserved.
 // https://github.com/golang/protobuf
 //
 // Redistribution and use in source and binary forms, with or without
@@ -29,12 +29,15 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-syntax = "proto2";
+syntax = "proto3";
 
-package imp;
+package goproto.test.import_public;
 
-option go_package = "github.com/golang/protobuf/protoc-gen-go/testdata/imp/imp3";
+option go_package = "github.com/golang/protobuf/protoc-gen-go/testdata/import_public";
 
-message ForeignImportedMessage {
-  optional string tuber = 1;
+import "import_public/sub/a.proto";
+
+message Local {
+  goproto.test.import_public.sub.M m = 1;
+  goproto.test.import_public.sub.E e = 2;
 }
diff --git a/protoc-gen-go/testdata/import_public/sub/a.pb.go b/protoc-gen-go/testdata/import_public/sub/a.pb.go
new file mode 100644
index 0000000000..4f8f6d2439
--- /dev/null
+++ b/protoc-gen-go/testdata/import_public/sub/a.pb.go
@@ -0,0 +1,100 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// source: import_public/sub/a.proto
+
+package sub // import "github.com/golang/protobuf/protoc-gen-go/testdata/import_public/sub"
+
+import proto "github.com/golang/protobuf/proto"
+import fmt "fmt"
+import math "math"
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+
+type E int32
+
+const (
+	E_ZERO E = 0
+)
+
+var E_name = map[int32]string{
+	0: "ZERO",
+}
+var E_value = map[string]int32{
+	"ZERO": 0,
+}
+
+func (x E) String() string {
+	return proto.EnumName(E_name, int32(x))
+}
+func (E) EnumDescriptor() ([]byte, []int) {
+	return fileDescriptor_a_91ca0264a534463a, []int{0}
+}
+
+type M struct {
+	// Field using a type in the same Go package, but a different source file.
+	M2                   *M2      `protobuf:"bytes,1,opt,name=m2" json:"m2,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *M) Reset()         { *m = M{} }
+func (m *M) String() string { return proto.CompactTextString(m) }
+func (*M) ProtoMessage()    {}
+func (*M) Descriptor() ([]byte, []int) {
+	return fileDescriptor_a_91ca0264a534463a, []int{0}
+}
+func (m *M) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_M.Unmarshal(m, b)
+}
+func (m *M) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_M.Marshal(b, m, deterministic)
+}
+func (dst *M) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_M.Merge(dst, src)
+}
+func (m *M) XXX_Size() int {
+	return xxx_messageInfo_M.Size(m)
+}
+func (m *M) XXX_DiscardUnknown() {
+	xxx_messageInfo_M.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_M proto.InternalMessageInfo
+
+func (m *M) GetM2() *M2 {
+	if m != nil {
+		return m.M2
+	}
+	return nil
+}
+
+func init() {
+	proto.RegisterType((*M)(nil), "goproto.test.import_public.sub.M")
+	proto.RegisterEnum("goproto.test.import_public.sub.E", E_name, E_value)
+}
+
+func init() { proto.RegisterFile("import_public/sub/a.proto", fileDescriptor_a_91ca0264a534463a) }
+
+var fileDescriptor_a_91ca0264a534463a = []byte{
+	// 172 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x92, 0xcc, 0xcc, 0x2d, 0xc8,
+	0x2f, 0x2a, 0x89, 0x2f, 0x28, 0x4d, 0xca, 0xc9, 0x4c, 0xd6, 0x2f, 0x2e, 0x4d, 0xd2, 0x4f, 0xd4,
+	0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0x92, 0x4b, 0xcf, 0x07, 0x33, 0xf4, 0x4a, 0x52, 0x8b, 0x4b,
+	0xf4, 0x50, 0xd4, 0xe9, 0x15, 0x97, 0x26, 0x49, 0x61, 0xd1, 0x9a, 0x04, 0xd1, 0xaa, 0x64, 0xce,
+	0xc5, 0xe8, 0x2b, 0x64, 0xc4, 0xc5, 0x94, 0x6b, 0x24, 0xc1, 0xa8, 0xc0, 0xa8, 0xc1, 0x6d, 0xa4,
+	0xa4, 0x87, 0xdf, 0x30, 0x3d, 0x5f, 0xa3, 0x20, 0xa6, 0x5c, 0x23, 0x2d, 0x5e, 0x2e, 0x46, 0x57,
+	0x21, 0x0e, 0x2e, 0x96, 0x28, 0xd7, 0x20, 0x7f, 0x01, 0x06, 0x27, 0xd7, 0x28, 0xe7, 0xf4, 0xcc,
+	0x92, 0x8c, 0xd2, 0x24, 0xbd, 0xe4, 0xfc, 0x5c, 0xfd, 0xf4, 0xfc, 0x9c, 0xc4, 0xbc, 0x74, 0x7d,
+	0xb0, 0x39, 0x49, 0xa5, 0x69, 0x10, 0x46, 0xb2, 0x6e, 0x7a, 0x6a, 0x9e, 0x6e, 0x7a, 0xbe, 0x3e,
+	0xc8, 0xe0, 0x94, 0xc4, 0x92, 0x44, 0x7d, 0x0c, 0x67, 0x25, 0xb1, 0x81, 0x55, 0x1a, 0x03, 0x02,
+	0x00, 0x00, 0xff, 0xff, 0x81, 0xcc, 0x07, 0x7d, 0xed, 0x00, 0x00, 0x00,
+}
diff --git a/protoc-gen-go/testdata/imp/imp2/imp2-enum.proto b/protoc-gen-go/testdata/import_public/sub/a.proto
similarity index 84%
rename from protoc-gen-go/testdata/imp/imp2/imp2-enum.proto
rename to protoc-gen-go/testdata/import_public/sub/a.proto
index b31a4f74f1..4494c818a6 100644
--- a/protoc-gen-go/testdata/imp/imp2/imp2-enum.proto
+++ b/protoc-gen-go/testdata/import_public/sub/a.proto
@@ -1,6 +1,6 @@
 // Go support for Protocol Buffers - Google's data interchange format
 //
-// Copyright 2011 The Go Authors.  All rights reserved.
+// Copyright 2018 The Go Authors.  All rights reserved.
 // https://github.com/golang/protobuf
 //
 // Redistribution and use in source and binary forms, with or without
@@ -29,14 +29,19 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-syntax = "proto2";
+syntax = "proto3";
 
-package imp;
+package goproto.test.import_public.sub;
 
-option go_package = "github.com/golang/protobuf/protoc-gen-go/testdata/imp/imp2";
+option go_package = "github.com/golang/protobuf/protoc-gen-go/testdata/import_public/sub";
 
-message EnumPB {
-  enum Type {
-    TYPE_1 = 0;
-  }
+import "import_public/sub/b.proto";
+
+message M {
+  // Field using a type in the same Go package, but a different source file.
+  M2 m2 = 1;
+}
+
+enum E {
+  ZERO = 0;
 }
diff --git a/protoc-gen-go/testdata/import_public/sub/b.pb.go b/protoc-gen-go/testdata/import_public/sub/b.pb.go
new file mode 100644
index 0000000000..d57a3bb9aa
--- /dev/null
+++ b/protoc-gen-go/testdata/import_public/sub/b.pb.go
@@ -0,0 +1,67 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// source: import_public/sub/b.proto
+
+package sub // import "github.com/golang/protobuf/protoc-gen-go/testdata/import_public/sub"
+
+import proto "github.com/golang/protobuf/proto"
+import fmt "fmt"
+import math "math"
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+
+type M2 struct {
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *M2) Reset()         { *m = M2{} }
+func (m *M2) String() string { return proto.CompactTextString(m) }
+func (*M2) ProtoMessage()    {}
+func (*M2) Descriptor() ([]byte, []int) {
+	return fileDescriptor_b_eba25180453d86b4, []int{0}
+}
+func (m *M2) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_M2.Unmarshal(m, b)
+}
+func (m *M2) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_M2.Marshal(b, m, deterministic)
+}
+func (dst *M2) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_M2.Merge(dst, src)
+}
+func (m *M2) XXX_Size() int {
+	return xxx_messageInfo_M2.Size(m)
+}
+func (m *M2) XXX_DiscardUnknown() {
+	xxx_messageInfo_M2.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_M2 proto.InternalMessageInfo
+
+func init() {
+	proto.RegisterType((*M2)(nil), "goproto.test.import_public.sub.M2")
+}
+
+func init() { proto.RegisterFile("import_public/sub/b.proto", fileDescriptor_b_eba25180453d86b4) }
+
+var fileDescriptor_b_eba25180453d86b4 = []byte{
+	// 127 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x92, 0xcc, 0xcc, 0x2d, 0xc8,
+	0x2f, 0x2a, 0x89, 0x2f, 0x28, 0x4d, 0xca, 0xc9, 0x4c, 0xd6, 0x2f, 0x2e, 0x4d, 0xd2, 0x4f, 0xd2,
+	0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0x92, 0x4b, 0xcf, 0x07, 0x33, 0xf4, 0x4a, 0x52, 0x8b, 0x4b,
+	0xf4, 0x50, 0xd4, 0xe9, 0x15, 0x97, 0x26, 0x29, 0xb1, 0x70, 0x31, 0xf9, 0x1a, 0x39, 0xb9, 0x46,
+	0x39, 0xa7, 0x67, 0x96, 0x64, 0x94, 0x26, 0xe9, 0x25, 0xe7, 0xe7, 0xea, 0xa7, 0xe7, 0xe7, 0x24,
+	0xe6, 0xa5, 0xeb, 0x83, 0xf5, 0x25, 0x95, 0xa6, 0x41, 0x18, 0xc9, 0xba, 0xe9, 0xa9, 0x79, 0xba,
+	0xe9, 0xf9, 0xfa, 0x20, 0x83, 0x52, 0x12, 0x4b, 0x12, 0xf5, 0x31, 0x2c, 0x4d, 0x62, 0x03, 0xab,
+	0x34, 0x06, 0x04, 0x00, 0x00, 0xff, 0xff, 0x64, 0x42, 0xe4, 0xa8, 0x90, 0x00, 0x00, 0x00,
+}
diff --git a/protoc-gen-go/testdata/imports/test_import_public.proto b/protoc-gen-go/testdata/import_public/sub/b.proto
similarity index 93%
rename from protoc-gen-go/testdata/imports/test_import_public.proto
rename to protoc-gen-go/testdata/import_public/sub/b.proto
index 7130cd8ea7..c7299e0f29 100644
--- a/protoc-gen-go/testdata/imports/test_import_public.proto
+++ b/protoc-gen-go/testdata/import_public/sub/b.proto
@@ -31,13 +31,9 @@
 
 syntax = "proto3";
 
-package test;
+package goproto.test.import_public.sub;
 
-option go_package = "github.com/golang/protobuf/protoc-gen-go/testdata/imports";
+option go_package = "github.com/golang/protobuf/protoc-gen-go/testdata/import_public/sub";
 
-import public "imports/test_a_1/m1.proto";
-
-message Public {
-  test.a.M1 m1 = 1;
-  test.a.E1 e1 = 2;
+message M2 {
 }
diff --git a/protoc-gen-go/testdata/import_public_test.go b/protoc-gen-go/testdata/import_public_test.go
new file mode 100644
index 0000000000..7ef776bf78
--- /dev/null
+++ b/protoc-gen-go/testdata/import_public_test.go
@@ -0,0 +1,66 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// 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.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// 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
+// OWNER 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 go1.9
+
+package testdata
+
+import (
+	"testing"
+
+	mainpb "github.com/golang/protobuf/protoc-gen-go/testdata/import_public"
+	subpb "github.com/golang/protobuf/protoc-gen-go/testdata/import_public/sub"
+)
+
+func TestImportPublicLink(t *testing.T) {
+	// mainpb.[ME] should be interchangable with subpb.[ME].
+	var _ mainpb.M = subpb.M{}
+	var _ mainpb.E = subpb.E(0)
+	_ = &mainpb.Public{
+		M: &mainpb.M{},
+		E: mainpb.E_ZERO,
+		Local: &mainpb.Local{
+			M: &mainpb.M{},
+			E: mainpb.E_ZERO,
+		},
+	}
+	_ = &mainpb.Public{
+		M: &subpb.M{},
+		E: subpb.E_ZERO,
+		Local: &mainpb.Local{
+			M: &subpb.M{},
+			E: subpb.E_ZERO,
+		},
+	}
+	_ = &mainpb.M{
+		M2: &subpb.M2{},
+	}
+}
diff --git a/protoc-gen-go/testdata/imports/test_import_public.pb.go b/protoc-gen-go/testdata/imports/test_import_public.pb.go
deleted file mode 100644
index 3725e05030..0000000000
--- a/protoc-gen-go/testdata/imports/test_import_public.pb.go
+++ /dev/null
@@ -1,126 +0,0 @@
-// Code generated by protoc-gen-go. DO NOT EDIT.
-// source: imports/test_import_public.proto
-
-package imports // import "github.com/golang/protobuf/protoc-gen-go/testdata/imports"
-
-import proto "github.com/golang/protobuf/proto"
-import fmt "fmt"
-import math "math"
-import test_a_1 "github.com/golang/protobuf/protoc-gen-go/testdata/imports/test_a_1"
-
-// Reference imports to suppress errors if they are not otherwise used.
-var _ = proto.Marshal
-var _ = fmt.Errorf
-var _ = math.Inf
-
-// This is a compile-time assertion to ensure that this generated file
-// is compatible with the proto package it is being compiled against.
-// A compilation error at this line likely means your copy of the
-// proto package needs to be updated.
-const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
-
-// M1 from public import imports/test_a_1/m1.proto
-type M1 test_a_1.M1
-
-func (m *M1) Reset()                         { (*test_a_1.M1)(m).Reset() }
-func (m *M1) String() string                 { return (*test_a_1.M1)(m).String() }
-func (*M1) ProtoMessage()                    {}
-func (m *M1) XXX_Unmarshal(buf []byte) error { return (*test_a_1.M1)(m).XXX_Unmarshal(buf) }
-func (m *M1) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
-	return (*test_a_1.M1)(m).XXX_Marshal(b, deterministic)
-}
-func (m *M1) XXX_Size() int       { return (*test_a_1.M1)(m).XXX_Size() }
-func (m *M1) XXX_DiscardUnknown() { (*test_a_1.M1)(m).XXX_DiscardUnknown() }
-
-// M1_1 from public import imports/test_a_1/m1.proto
-type M1_1 test_a_1.M1_1
-
-func (m *M1_1) Reset()                         { (*test_a_1.M1_1)(m).Reset() }
-func (m *M1_1) String() string                 { return (*test_a_1.M1_1)(m).String() }
-func (*M1_1) ProtoMessage()                    {}
-func (m *M1_1) XXX_Unmarshal(buf []byte) error { return (*test_a_1.M1_1)(m).XXX_Unmarshal(buf) }
-func (m *M1_1) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
-	return (*test_a_1.M1_1)(m).XXX_Marshal(b, deterministic)
-}
-func (m *M1_1) XXX_Size() int       { return (*test_a_1.M1_1)(m).XXX_Size() }
-func (m *M1_1) XXX_DiscardUnknown() { (*test_a_1.M1_1)(m).XXX_DiscardUnknown() }
-func (m *M1_1) GetM1() *M1          { return (*M1)((*test_a_1.M1_1)(m).GetM1()) }
-
-// E1 from public import imports/test_a_1/m1.proto
-type E1 test_a_1.E1
-
-var E1_name = test_a_1.E1_name
-var E1_value = test_a_1.E1_value
-
-func (x E1) String() string { return (test_a_1.E1)(x).String() }
-
-const E1_E1_ZERO = E1(test_a_1.E1_E1_ZERO)
-
-type Public struct {
-	M1                   *test_a_1.M1 `protobuf:"bytes,1,opt,name=m1" json:"m1,omitempty"`
-	E1                   test_a_1.E1  `protobuf:"varint,2,opt,name=e1,enum=test.a.E1" json:"e1,omitempty"`
-	XXX_NoUnkeyedLiteral struct{}     `json:"-"`
-	XXX_unrecognized     []byte       `json:"-"`
-	XXX_sizecache        int32        `json:"-"`
-}
-
-func (m *Public) Reset()         { *m = Public{} }
-func (m *Public) String() string { return proto.CompactTextString(m) }
-func (*Public) ProtoMessage()    {}
-func (*Public) Descriptor() ([]byte, []int) {
-	return fileDescriptor_test_import_public_b5b1d653c96016f3, []int{0}
-}
-func (m *Public) XXX_Unmarshal(b []byte) error {
-	return xxx_messageInfo_Public.Unmarshal(m, b)
-}
-func (m *Public) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
-	return xxx_messageInfo_Public.Marshal(b, m, deterministic)
-}
-func (dst *Public) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_Public.Merge(dst, src)
-}
-func (m *Public) XXX_Size() int {
-	return xxx_messageInfo_Public.Size(m)
-}
-func (m *Public) XXX_DiscardUnknown() {
-	xxx_messageInfo_Public.DiscardUnknown(m)
-}
-
-var xxx_messageInfo_Public proto.InternalMessageInfo
-
-func (m *Public) GetM1() *test_a_1.M1 {
-	if m != nil {
-		return m.M1
-	}
-	return nil
-}
-
-func (m *Public) GetE1() test_a_1.E1 {
-	if m != nil {
-		return m.E1
-	}
-	return test_a_1.E1_E1_ZERO
-}
-
-func init() {
-	proto.RegisterType((*Public)(nil), "test.Public")
-}
-
-func init() {
-	proto.RegisterFile("imports/test_import_public.proto", fileDescriptor_test_import_public_b5b1d653c96016f3)
-}
-
-var fileDescriptor_test_import_public_b5b1d653c96016f3 = []byte{
-	// 174 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x52, 0xc8, 0xcc, 0x2d, 0xc8,
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-	0xa4, 0xb8, 0x98, 0x72, 0x0d, 0x25, 0x18, 0x15, 0x18, 0x35, 0xb8, 0x8d, 0xb8, 0xf4, 0x40, 0x2a,
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-	0x8c, 0x1a, 0x7c, 0x08, 0x39, 0x57, 0xc3, 0x20, 0xa6, 0x54, 0x43, 0x27, 0xeb, 0x28, 0xcb, 0xf4,
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-	0x7d, 0xb0, 0xe1, 0x49, 0xa5, 0x69, 0x10, 0x46, 0xb2, 0x6e, 0x7a, 0x6a, 0x9e, 0x6e, 0x7a, 0x3e,
-	0xd8, 0xfe, 0x94, 0xc4, 0x92, 0x44, 0x7d, 0xa8, 0x83, 0x02, 0x18, 0x92, 0xd8, 0xc0, 0x2a, 0x8c,
-	0x01, 0x01, 0x00, 0x00, 0xff, 0xff, 0x65, 0x95, 0x6f, 0xe5, 0xcc, 0x00, 0x00, 0x00,
-}
diff --git a/protoc-gen-go/testdata/main_test.go b/protoc-gen-go/testdata/main_test.go
index 87ee1681cd..7ec1f2dbaa 100644
--- a/protoc-gen-go/testdata/main_test.go
+++ b/protoc-gen-go/testdata/main_test.go
@@ -36,7 +36,6 @@ package testdata
 import (
 	"testing"
 
-	imppb "github.com/golang/protobuf/protoc-gen-go/testdata/imp"
 	importspb "github.com/golang/protobuf/protoc-gen-go/testdata/imports"
 	multipb "github.com/golang/protobuf/protoc-gen-go/testdata/multi"
 	mytestpb "github.com/golang/protobuf/protoc-gen-go/testdata/my_test"
@@ -46,5 +45,4 @@ func TestLink(t *testing.T) {
 	_ = &multipb.Multi1{}
 	_ = &mytestpb.Request{}
 	_ = &importspb.All{}
-	_ = &imppb.ImportedMessage{}
 }
diff --git a/regenerate.sh b/regenerate.sh
index a1976be3db..1024b9cdf2 100755
--- a/regenerate.sh
+++ b/regenerate.sh
@@ -9,6 +9,12 @@ mkdir -p $tmpdir/bin
 PATH=$tmpdir/bin:$PATH
 GOBIN=$tmpdir/bin go install ./protoc-gen-go
 
+# Public imports require at least Go 1.9.
+supportTypeAliases=0
+if go list -f '{{context.ReleaseTags}}' runtime | grep -q go1.9; then
+  supportTypeAliases=1
+fi
+
 # Generate various test protos.
 PROTO_DIRS=(
   conformance/internal/conformance_proto
@@ -18,6 +24,10 @@ PROTO_DIRS=(
 )
 for dir in ${PROTO_DIRS[@]}; do
   for p in `find $dir -name "*.proto"`; do
+    if [[ $p == */import_public/* && ! $supportTypeAliases ]]; then
+      echo "# $p (skipped)"
+      continue;
+    fi
     echo "# $p"
     protoc -I$dir --go_out=plugins=grpc,paths=source_relative:$dir $p
   done