diff --git a/examples/proto/examplepb/a_bit_of_everything.pb.go b/examples/proto/examplepb/a_bit_of_everything.pb.go
index 520dae9c337..32c3d2d0b68 100644
--- a/examples/proto/examplepb/a_bit_of_everything.pb.go
+++ b/examples/proto/examplepb/a_bit_of_everything.pb.go
@@ -85,37 +85,37 @@ func (ABitOfEverything_Nested_DeepEnum) EnumDescriptor() ([]byte, []int) {
 // Intentionaly complicated message type to cover much features of Protobuf.
 // NEXT ID: 30
 type ABitOfEverything struct {
-	SingleNested        *ABitOfEverything_Nested   `protobuf:"bytes,25,opt,name=single_nested,json=singleNested" json:"single_nested,omitempty"`
-	Uuid                string                     `protobuf:"bytes,1,opt,name=uuid" json:"uuid,omitempty"`
-	Nested              []*ABitOfEverything_Nested `protobuf:"bytes,2,rep,name=nested" json:"nested,omitempty"`
-	FloatValue          float32                    `protobuf:"fixed32,3,opt,name=float_value,json=floatValue" json:"float_value,omitempty"`
-	DoubleValue         float64                    `protobuf:"fixed64,4,opt,name=double_value,json=doubleValue" json:"double_value,omitempty"`
-	Int64Value          int64                      `protobuf:"varint,5,opt,name=int64_value,json=int64Value" json:"int64_value,omitempty"`
-	Uint64Value         uint64                     `protobuf:"varint,6,opt,name=uint64_value,json=uint64Value" json:"uint64_value,omitempty"`
-	Int32Value          int32                      `protobuf:"varint,7,opt,name=int32_value,json=int32Value" json:"int32_value,omitempty"`
-	Fixed64Value        uint64                     `protobuf:"fixed64,8,opt,name=fixed64_value,json=fixed64Value" json:"fixed64_value,omitempty"`
-	Fixed32Value        uint32                     `protobuf:"fixed32,9,opt,name=fixed32_value,json=fixed32Value" json:"fixed32_value,omitempty"`
-	BoolValue           bool                       `protobuf:"varint,10,opt,name=bool_value,json=boolValue" json:"bool_value,omitempty"`
-	StringValue         string                     `protobuf:"bytes,11,opt,name=string_value,json=stringValue" json:"string_value,omitempty"`
+	SingleNested        *ABitOfEverything_Nested   `protobuf:"bytes,25,opt,name=single_nested,json=singleNested,proto3" json:"single_nested,omitempty"`
+	Uuid                string                     `protobuf:"bytes,1,opt,name=uuid,proto3" json:"uuid,omitempty"`
+	Nested              []*ABitOfEverything_Nested `protobuf:"bytes,2,rep,name=nested,proto3" json:"nested,omitempty"`
+	FloatValue          float32                    `protobuf:"fixed32,3,opt,name=float_value,json=floatValue,proto3" json:"float_value,omitempty"`
+	DoubleValue         float64                    `protobuf:"fixed64,4,opt,name=double_value,json=doubleValue,proto3" json:"double_value,omitempty"`
+	Int64Value          int64                      `protobuf:"varint,5,opt,name=int64_value,json=int64Value,proto3" json:"int64_value,omitempty"`
+	Uint64Value         uint64                     `protobuf:"varint,6,opt,name=uint64_value,json=uint64Value,proto3" json:"uint64_value,omitempty"`
+	Int32Value          int32                      `protobuf:"varint,7,opt,name=int32_value,json=int32Value,proto3" json:"int32_value,omitempty"`
+	Fixed64Value        uint64                     `protobuf:"fixed64,8,opt,name=fixed64_value,json=fixed64Value,proto3" json:"fixed64_value,omitempty"`
+	Fixed32Value        uint32                     `protobuf:"fixed32,9,opt,name=fixed32_value,json=fixed32Value,proto3" json:"fixed32_value,omitempty"`
+	BoolValue           bool                       `protobuf:"varint,10,opt,name=bool_value,json=boolValue,proto3" json:"bool_value,omitempty"`
+	StringValue         string                     `protobuf:"bytes,11,opt,name=string_value,json=stringValue,proto3" json:"string_value,omitempty"`
 	BytesValue          []byte                     `protobuf:"bytes,29,opt,name=bytes_value,json=bytesValue,proto3" json:"bytes_value,omitempty"`
-	Uint32Value         uint32                     `protobuf:"varint,13,opt,name=uint32_value,json=uint32Value" json:"uint32_value,omitempty"`
-	EnumValue           NumericEnum                `protobuf:"varint,14,opt,name=enum_value,json=enumValue,enum=grpc.gateway.examples.examplepb.NumericEnum" json:"enum_value,omitempty"`
-	Sfixed32Value       int32                      `protobuf:"fixed32,15,opt,name=sfixed32_value,json=sfixed32Value" json:"sfixed32_value,omitempty"`
-	Sfixed64Value       int64                      `protobuf:"fixed64,16,opt,name=sfixed64_value,json=sfixed64Value" json:"sfixed64_value,omitempty"`
-	Sint32Value         int32                      `protobuf:"zigzag32,17,opt,name=sint32_value,json=sint32Value" json:"sint32_value,omitempty"`
-	Sint64Value         int64                      `protobuf:"zigzag64,18,opt,name=sint64_value,json=sint64Value" json:"sint64_value,omitempty"`
-	RepeatedStringValue []string                   `protobuf:"bytes,19,rep,name=repeated_string_value,json=repeatedStringValue" json:"repeated_string_value,omitempty"`
+	Uint32Value         uint32                     `protobuf:"varint,13,opt,name=uint32_value,json=uint32Value,proto3" json:"uint32_value,omitempty"`
+	EnumValue           NumericEnum                `protobuf:"varint,14,opt,name=enum_value,json=enumValue,proto3,enum=grpc.gateway.examples.examplepb.NumericEnum" json:"enum_value,omitempty"`
+	Sfixed32Value       int32                      `protobuf:"fixed32,15,opt,name=sfixed32_value,json=sfixed32Value,proto3" json:"sfixed32_value,omitempty"`
+	Sfixed64Value       int64                      `protobuf:"fixed64,16,opt,name=sfixed64_value,json=sfixed64Value,proto3" json:"sfixed64_value,omitempty"`
+	Sint32Value         int32                      `protobuf:"zigzag32,17,opt,name=sint32_value,json=sint32Value,proto3" json:"sint32_value,omitempty"`
+	Sint64Value         int64                      `protobuf:"zigzag64,18,opt,name=sint64_value,json=sint64Value,proto3" json:"sint64_value,omitempty"`
+	RepeatedStringValue []string                   `protobuf:"bytes,19,rep,name=repeated_string_value,json=repeatedStringValue,proto3" json:"repeated_string_value,omitempty"`
 	// Types that are valid to be assigned to OneofValue:
 	//	*ABitOfEverything_OneofEmpty
 	//	*ABitOfEverything_OneofString
 	OneofValue               isABitOfEverything_OneofValue       `protobuf_oneof:"oneof_value"`
-	MapValue                 map[string]NumericEnum              `protobuf:"bytes,22,rep,name=map_value,json=mapValue" json:"map_value,omitempty" protobuf_key:"bytes,1,opt,name=key" protobuf_val:"varint,2,opt,name=value,enum=grpc.gateway.examples.examplepb.NumericEnum"`
-	MappedStringValue        map[string]string                   `protobuf:"bytes,23,rep,name=mapped_string_value,json=mappedStringValue" json:"mapped_string_value,omitempty" protobuf_key:"bytes,1,opt,name=key" protobuf_val:"bytes,2,opt,name=value"`
-	MappedNestedValue        map[string]*ABitOfEverything_Nested `protobuf:"bytes,24,rep,name=mapped_nested_value,json=mappedNestedValue" json:"mapped_nested_value,omitempty" protobuf_key:"bytes,1,opt,name=key" protobuf_val:"bytes,2,opt,name=value"`
-	NonConventionalNameValue string                              `protobuf:"bytes,26,opt,name=nonConventionalNameValue" json:"nonConventionalNameValue,omitempty"`
-	TimestampValue           *timestamp.Timestamp                `protobuf:"bytes,27,opt,name=timestamp_value,json=timestampValue" json:"timestamp_value,omitempty"`
+	MapValue                 map[string]NumericEnum              `protobuf:"bytes,22,rep,name=map_value,json=mapValue,proto3" json:"map_value,omitempty" protobuf_key:"bytes,1,opt,name=key,proto3" protobuf_val:"varint,2,opt,name=value,proto3,enum=grpc.gateway.examples.examplepb.NumericEnum"`
+	MappedStringValue        map[string]string                   `protobuf:"bytes,23,rep,name=mapped_string_value,json=mappedStringValue,proto3" json:"mapped_string_value,omitempty" protobuf_key:"bytes,1,opt,name=key,proto3" protobuf_val:"bytes,2,opt,name=value,proto3"`
+	MappedNestedValue        map[string]*ABitOfEverything_Nested `protobuf:"bytes,24,rep,name=mapped_nested_value,json=mappedNestedValue,proto3" json:"mapped_nested_value,omitempty" protobuf_key:"bytes,1,opt,name=key,proto3" protobuf_val:"bytes,2,opt,name=value,proto3"`
+	NonConventionalNameValue string                              `protobuf:"bytes,26,opt,name=nonConventionalNameValue,proto3" json:"nonConventionalNameValue,omitempty"`
+	TimestampValue           *timestamp.Timestamp                `protobuf:"bytes,27,opt,name=timestamp_value,json=timestampValue,proto3" json:"timestamp_value,omitempty"`
 	// repeated enum value. it is comma-separated in query
-	RepeatedEnumValue    []NumericEnum `protobuf:"varint,28,rep,packed,name=repeated_enum_value,json=repeatedEnumValue,enum=grpc.gateway.examples.examplepb.NumericEnum" json:"repeated_enum_value,omitempty"`
+	RepeatedEnumValue    []NumericEnum `protobuf:"varint,28,rep,packed,name=repeated_enum_value,json=repeatedEnumValue,proto3,enum=grpc.gateway.examples.examplepb.NumericEnum" json:"repeated_enum_value,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}      `json:"-"`
 	XXX_unrecognized     []byte        `json:"-"`
 	XXX_sizecache        int32         `json:"-"`
@@ -150,10 +150,10 @@ type isABitOfEverything_OneofValue interface {
 }
 
 type ABitOfEverything_OneofEmpty struct {
-	OneofEmpty *empty.Empty `protobuf:"bytes,20,opt,name=oneof_empty,json=oneofEmpty,oneof"`
+	OneofEmpty *empty.Empty `protobuf:"bytes,20,opt,name=oneof_empty,json=oneofEmpty,proto3,oneof"`
 }
 type ABitOfEverything_OneofString struct {
-	OneofString string `protobuf:"bytes,21,opt,name=oneof_string,json=oneofString,oneof"`
+	OneofString string `protobuf:"bytes,21,opt,name=oneof_string,json=oneofString,proto3,oneof"`
 }
 
 func (*ABitOfEverything_OneofEmpty) isABitOfEverything_OneofValue()  {}
@@ -435,9 +435,9 @@ func _ABitOfEverything_OneofSizer(msg proto.Message) (n int) {
 // Nested is nested type.
 type ABitOfEverything_Nested struct {
 	// name is nested field.
-	Name                 string                           `protobuf:"bytes,1,opt,name=name" json:"name,omitempty"`
-	Amount               uint32                           `protobuf:"varint,2,opt,name=amount" json:"amount,omitempty"`
-	Ok                   ABitOfEverything_Nested_DeepEnum `protobuf:"varint,3,opt,name=ok,enum=grpc.gateway.examples.examplepb.ABitOfEverything_Nested_DeepEnum" json:"ok,omitempty"`
+	Name                 string                           `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
+	Amount               uint32                           `protobuf:"varint,2,opt,name=amount,proto3" json:"amount,omitempty"`
+	Ok                   ABitOfEverything_Nested_DeepEnum `protobuf:"varint,3,opt,name=ok,proto3,enum=grpc.gateway.examples.examplepb.ABitOfEverything_Nested_DeepEnum" json:"ok,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}                         `json:"-"`
 	XXX_unrecognized     []byte                           `json:"-"`
 	XXX_sizecache        int32                            `json:"-"`
@@ -489,7 +489,7 @@ func (m *ABitOfEverything_Nested) GetOk() ABitOfEverything_Nested_DeepEnum {
 }
 
 type Body struct {
-	Name                 string   `protobuf:"bytes,1,opt,name=name" json:"name,omitempty"`
+	Name                 string   `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
@@ -527,8 +527,8 @@ func (m *Body) GetName() string {
 }
 
 type MessageWithBody struct {
-	Id                   string   `protobuf:"bytes,1,opt,name=id" json:"id,omitempty"`
-	Data                 *Body    `protobuf:"bytes,2,opt,name=data" json:"data,omitempty"`
+	Id                   string   `protobuf:"bytes,1,opt,name=id,proto3" json:"id,omitempty"`
+	Data                 *Body    `protobuf:"bytes,2,opt,name=data,proto3" json:"data,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
diff --git a/examples/proto/examplepb/echo_service.pb.go b/examples/proto/examplepb/echo_service.pb.go
index 42a70d155e9..c99f75b69cc 100644
--- a/examples/proto/examplepb/echo_service.pb.go
+++ b/examples/proto/examplepb/echo_service.pb.go
@@ -71,10 +71,10 @@ type isEmbedded_Mark interface {
 }
 
 type Embedded_Progress struct {
-	Progress int64 `protobuf:"varint,1,opt,name=progress,oneof"`
+	Progress int64 `protobuf:"varint,1,opt,name=progress,proto3,oneof"`
 }
 type Embedded_Note struct {
-	Note string `protobuf:"bytes,2,opt,name=note,oneof"`
+	Note string `protobuf:"bytes,2,opt,name=note,proto3,oneof"`
 }
 
 func (*Embedded_Progress) isEmbedded_Mark() {}
@@ -169,13 +169,13 @@ func _Embedded_OneofSizer(msg proto.Message) (n int) {
 // SimpleMessage represents a simple message sent to the Echo service.
 type SimpleMessage struct {
 	// Id represents the message identifier.
-	Id  string `protobuf:"bytes,1,opt,name=id" json:"id,omitempty"`
-	Num int64  `protobuf:"varint,2,opt,name=num" json:"num,omitempty"`
+	Id  string `protobuf:"bytes,1,opt,name=id,proto3" json:"id,omitempty"`
+	Num int64  `protobuf:"varint,2,opt,name=num,proto3" json:"num,omitempty"`
 	// Types that are valid to be assigned to Code:
 	//	*SimpleMessage_LineNum
 	//	*SimpleMessage_Lang
 	Code   isSimpleMessage_Code `protobuf_oneof:"code"`
-	Status *Embedded            `protobuf:"bytes,5,opt,name=status" json:"status,omitempty"`
+	Status *Embedded            `protobuf:"bytes,5,opt,name=status,proto3" json:"status,omitempty"`
 	// Types that are valid to be assigned to Ext:
 	//	*SimpleMessage_En
 	//	*SimpleMessage_No
@@ -217,16 +217,16 @@ type isSimpleMessage_Ext interface {
 }
 
 type SimpleMessage_LineNum struct {
-	LineNum int64 `protobuf:"varint,3,opt,name=line_num,json=lineNum,oneof"`
+	LineNum int64 `protobuf:"varint,3,opt,name=line_num,json=lineNum,proto3,oneof"`
 }
 type SimpleMessage_Lang struct {
-	Lang string `protobuf:"bytes,4,opt,name=lang,oneof"`
+	Lang string `protobuf:"bytes,4,opt,name=lang,proto3,oneof"`
 }
 type SimpleMessage_En struct {
-	En int64 `protobuf:"varint,6,opt,name=en,oneof"`
+	En int64 `protobuf:"varint,6,opt,name=en,proto3,oneof"`
 }
 type SimpleMessage_No struct {
-	No *Embedded `protobuf:"bytes,7,opt,name=no,oneof"`
+	No *Embedded `protobuf:"bytes,7,opt,name=no,proto3,oneof"`
 }
 
 func (*SimpleMessage_LineNum) isSimpleMessage_Code() {}
diff --git a/examples/proto/examplepb/flow_combination.pb.go b/examples/proto/examplepb/flow_combination.pb.go
index 55be4381b5e..25e2b775e50 100644
--- a/examples/proto/examplepb/flow_combination.pb.go
+++ b/examples/proto/examplepb/flow_combination.pb.go
@@ -55,9 +55,9 @@ func (m *EmptyProto) XXX_DiscardUnknown() {
 var xxx_messageInfo_EmptyProto proto.InternalMessageInfo
 
 type NonEmptyProto struct {
-	A                    string   `protobuf:"bytes,1,opt,name=a" json:"a,omitempty"`
-	B                    string   `protobuf:"bytes,2,opt,name=b" json:"b,omitempty"`
-	C                    string   `protobuf:"bytes,3,opt,name=c" json:"c,omitempty"`
+	A                    string   `protobuf:"bytes,1,opt,name=a,proto3" json:"a,omitempty"`
+	B                    string   `protobuf:"bytes,2,opt,name=b,proto3" json:"b,omitempty"`
+	C                    string   `protobuf:"bytes,3,opt,name=c,proto3" json:"c,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
@@ -109,7 +109,7 @@ func (m *NonEmptyProto) GetC() string {
 }
 
 type UnaryProto struct {
-	Str                  string   `protobuf:"bytes,1,opt,name=str" json:"str,omitempty"`
+	Str                  string   `protobuf:"bytes,1,opt,name=str,proto3" json:"str,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
@@ -147,9 +147,9 @@ func (m *UnaryProto) GetStr() string {
 }
 
 type NestedProto struct {
-	A                    *UnaryProto `protobuf:"bytes,1,opt,name=a" json:"a,omitempty"`
-	B                    string      `protobuf:"bytes,2,opt,name=b" json:"b,omitempty"`
-	C                    string      `protobuf:"bytes,3,opt,name=c" json:"c,omitempty"`
+	A                    *UnaryProto `protobuf:"bytes,1,opt,name=a,proto3" json:"a,omitempty"`
+	B                    string      `protobuf:"bytes,2,opt,name=b,proto3" json:"b,omitempty"`
+	C                    string      `protobuf:"bytes,3,opt,name=c,proto3" json:"c,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}    `json:"-"`
 	XXX_unrecognized     []byte      `json:"-"`
 	XXX_sizecache        int32       `json:"-"`
@@ -201,7 +201,7 @@ func (m *NestedProto) GetC() string {
 }
 
 type SingleNestedProto struct {
-	A                    *UnaryProto `protobuf:"bytes,1,opt,name=a" json:"a,omitempty"`
+	A                    *UnaryProto `protobuf:"bytes,1,opt,name=a,proto3" json:"a,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}    `json:"-"`
 	XXX_unrecognized     []byte      `json:"-"`
 	XXX_sizecache        int32       `json:"-"`
diff --git a/examples/proto/examplepb/unannotated_echo_service.pb.go b/examples/proto/examplepb/unannotated_echo_service.pb.go
index 733ab6e8162..28f0d7311d0 100644
--- a/examples/proto/examplepb/unannotated_echo_service.pb.go
+++ b/examples/proto/examplepb/unannotated_echo_service.pb.go
@@ -37,9 +37,9 @@ const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
 // UnannotatedSimpleMessage represents a simple message sent to the unannotated Echo service.
 type UnannotatedSimpleMessage struct {
 	// Id represents the message identifier.
-	Id                   string             `protobuf:"bytes,1,opt,name=id" json:"id,omitempty"`
-	Num                  int64              `protobuf:"varint,2,opt,name=num" json:"num,omitempty"`
-	Duration             *duration.Duration `protobuf:"bytes,3,opt,name=duration" json:"duration,omitempty"`
+	Id                   string             `protobuf:"bytes,1,opt,name=id,proto3" json:"id,omitempty"`
+	Num                  int64              `protobuf:"varint,2,opt,name=num,proto3" json:"num,omitempty"`
+	Duration             *duration.Duration `protobuf:"bytes,3,opt,name=duration,proto3" json:"duration,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}           `json:"-"`
 	XXX_unrecognized     []byte             `json:"-"`
 	XXX_sizecache        int32              `json:"-"`
diff --git a/examples/proto/examplepb/wrappers.pb.go b/examples/proto/examplepb/wrappers.pb.go
index a5065f9d378..f3caeaf4e6b 100644
--- a/examples/proto/examplepb/wrappers.pb.go
+++ b/examples/proto/examplepb/wrappers.pb.go
@@ -26,12 +26,12 @@ var _ = math.Inf
 const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
 
 type Wrappers struct {
-	StringValue          *wrappers.StringValue `protobuf:"bytes,1,opt,name=string_value,json=stringValue" json:"string_value,omitempty"`
-	Int32Value           *wrappers.Int32Value  `protobuf:"bytes,2,opt,name=int32_value,json=int32Value" json:"int32_value,omitempty"`
-	Int64Value           *wrappers.Int64Value  `protobuf:"bytes,3,opt,name=int64_value,json=int64Value" json:"int64_value,omitempty"`
-	FloatValue           *wrappers.FloatValue  `protobuf:"bytes,4,opt,name=float_value,json=floatValue" json:"float_value,omitempty"`
-	DoubleValue          *wrappers.DoubleValue `protobuf:"bytes,5,opt,name=double_value,json=doubleValue" json:"double_value,omitempty"`
-	BoolValue            *wrappers.BoolValue   `protobuf:"bytes,6,opt,name=bool_value,json=boolValue" json:"bool_value,omitempty"`
+	StringValue          *wrappers.StringValue `protobuf:"bytes,1,opt,name=string_value,json=stringValue,proto3" json:"string_value,omitempty"`
+	Int32Value           *wrappers.Int32Value  `protobuf:"bytes,2,opt,name=int32_value,json=int32Value,proto3" json:"int32_value,omitempty"`
+	Int64Value           *wrappers.Int64Value  `protobuf:"bytes,3,opt,name=int64_value,json=int64Value,proto3" json:"int64_value,omitempty"`
+	FloatValue           *wrappers.FloatValue  `protobuf:"bytes,4,opt,name=float_value,json=floatValue,proto3" json:"float_value,omitempty"`
+	DoubleValue          *wrappers.DoubleValue `protobuf:"bytes,5,opt,name=double_value,json=doubleValue,proto3" json:"double_value,omitempty"`
+	BoolValue            *wrappers.BoolValue   `protobuf:"bytes,6,opt,name=bool_value,json=boolValue,proto3" json:"bool_value,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}              `json:"-"`
 	XXX_unrecognized     []byte                `json:"-"`
 	XXX_sizecache        int32                 `json:"-"`
diff --git a/examples/proto/sub2/message.pb.go b/examples/proto/sub2/message.pb.go
index a0a812c7d0f..6819b67ae3c 100644
--- a/examples/proto/sub2/message.pb.go
+++ b/examples/proto/sub2/message.pb.go
@@ -19,7 +19,7 @@ var _ = math.Inf
 const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
 
 type IdMessage struct {
-	Uuid                 string   `protobuf:"bytes,1,opt,name=uuid" json:"uuid,omitempty"`
+	Uuid                 string   `protobuf:"bytes,1,opt,name=uuid,proto3" json:"uuid,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
diff --git a/protoc-gen-swagger/options/openapiv2.pb.go b/protoc-gen-swagger/options/openapiv2.pb.go
index be2342b7154..0b0f89d817f 100644
--- a/protoc-gen-swagger/options/openapiv2.pb.go
+++ b/protoc-gen-swagger/options/openapiv2.pb.go
@@ -190,16 +190,16 @@ func (SecurityScheme_Flow) EnumDescriptor() ([]byte, []int) {
 //
 // TODO(ivucica): document fields
 type Swagger struct {
-	Swagger              string                  `protobuf:"bytes,1,opt,name=swagger" json:"swagger,omitempty"`
-	Info                 *Info                   `protobuf:"bytes,2,opt,name=info" json:"info,omitempty"`
-	Host                 string                  `protobuf:"bytes,3,opt,name=host" json:"host,omitempty"`
-	BasePath             string                  `protobuf:"bytes,4,opt,name=base_path,json=basePath" json:"base_path,omitempty"`
-	Schemes              []Swagger_SwaggerScheme `protobuf:"varint,5,rep,packed,name=schemes,enum=grpc.gateway.protoc_gen_swagger.options.Swagger_SwaggerScheme" json:"schemes,omitempty"`
-	Consumes             []string                `protobuf:"bytes,6,rep,name=consumes" json:"consumes,omitempty"`
-	Produces             []string                `protobuf:"bytes,7,rep,name=produces" json:"produces,omitempty"`
-	SecurityDefinitions  *SecurityDefinitions    `protobuf:"bytes,11,opt,name=security_definitions,json=securityDefinitions" json:"security_definitions,omitempty"`
-	Security             []*SecurityRequirement  `protobuf:"bytes,12,rep,name=security" json:"security,omitempty"`
-	ExternalDocs         *ExternalDocumentation  `protobuf:"bytes,14,opt,name=external_docs,json=externalDocs" json:"external_docs,omitempty"`
+	Swagger              string                  `protobuf:"bytes,1,opt,name=swagger,proto3" json:"swagger,omitempty"`
+	Info                 *Info                   `protobuf:"bytes,2,opt,name=info,proto3" json:"info,omitempty"`
+	Host                 string                  `protobuf:"bytes,3,opt,name=host,proto3" json:"host,omitempty"`
+	BasePath             string                  `protobuf:"bytes,4,opt,name=base_path,json=basePath,proto3" json:"base_path,omitempty"`
+	Schemes              []Swagger_SwaggerScheme `protobuf:"varint,5,rep,packed,name=schemes,proto3,enum=grpc.gateway.protoc_gen_swagger.options.Swagger_SwaggerScheme" json:"schemes,omitempty"`
+	Consumes             []string                `protobuf:"bytes,6,rep,name=consumes,proto3" json:"consumes,omitempty"`
+	Produces             []string                `protobuf:"bytes,7,rep,name=produces,proto3" json:"produces,omitempty"`
+	SecurityDefinitions  *SecurityDefinitions    `protobuf:"bytes,11,opt,name=security_definitions,json=securityDefinitions,proto3" json:"security_definitions,omitempty"`
+	Security             []*SecurityRequirement  `protobuf:"bytes,12,rep,name=security,proto3" json:"security,omitempty"`
+	ExternalDocs         *ExternalDocumentation  `protobuf:"bytes,14,opt,name=external_docs,json=externalDocs,proto3" json:"external_docs,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}                `json:"-"`
 	XXX_unrecognized     []byte                  `json:"-"`
 	XXX_sizecache        int32                   `json:"-"`
@@ -305,16 +305,16 @@ func (m *Swagger) GetExternalDocs() *ExternalDocumentation {
 //
 // TODO(ivucica): document fields
 type Operation struct {
-	Tags                 []string               `protobuf:"bytes,1,rep,name=tags" json:"tags,omitempty"`
-	Summary              string                 `protobuf:"bytes,2,opt,name=summary" json:"summary,omitempty"`
-	Description          string                 `protobuf:"bytes,3,opt,name=description" json:"description,omitempty"`
-	ExternalDocs         *ExternalDocumentation `protobuf:"bytes,4,opt,name=external_docs,json=externalDocs" json:"external_docs,omitempty"`
-	OperationId          string                 `protobuf:"bytes,5,opt,name=operation_id,json=operationId" json:"operation_id,omitempty"`
-	Consumes             []string               `protobuf:"bytes,6,rep,name=consumes" json:"consumes,omitempty"`
-	Produces             []string               `protobuf:"bytes,7,rep,name=produces" json:"produces,omitempty"`
-	Schemes              []string               `protobuf:"bytes,10,rep,name=schemes" json:"schemes,omitempty"`
-	Deprecated           bool                   `protobuf:"varint,11,opt,name=deprecated" json:"deprecated,omitempty"`
-	Security             []*SecurityRequirement `protobuf:"bytes,12,rep,name=security" json:"security,omitempty"`
+	Tags                 []string               `protobuf:"bytes,1,rep,name=tags,proto3" json:"tags,omitempty"`
+	Summary              string                 `protobuf:"bytes,2,opt,name=summary,proto3" json:"summary,omitempty"`
+	Description          string                 `protobuf:"bytes,3,opt,name=description,proto3" json:"description,omitempty"`
+	ExternalDocs         *ExternalDocumentation `protobuf:"bytes,4,opt,name=external_docs,json=externalDocs,proto3" json:"external_docs,omitempty"`
+	OperationId          string                 `protobuf:"bytes,5,opt,name=operation_id,json=operationId,proto3" json:"operation_id,omitempty"`
+	Consumes             []string               `protobuf:"bytes,6,rep,name=consumes,proto3" json:"consumes,omitempty"`
+	Produces             []string               `protobuf:"bytes,7,rep,name=produces,proto3" json:"produces,omitempty"`
+	Schemes              []string               `protobuf:"bytes,10,rep,name=schemes,proto3" json:"schemes,omitempty"`
+	Deprecated           bool                   `protobuf:"varint,11,opt,name=deprecated,proto3" json:"deprecated,omitempty"`
+	Security             []*SecurityRequirement `protobuf:"bytes,12,rep,name=security,proto3" json:"security,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}               `json:"-"`
 	XXX_unrecognized     []byte                 `json:"-"`
 	XXX_sizecache        int32                  `json:"-"`
@@ -420,11 +420,11 @@ func (m *Operation) GetSecurity() []*SecurityRequirement {
 //
 // TODO(ivucica): document fields
 type Info struct {
-	Title                string   `protobuf:"bytes,1,opt,name=title" json:"title,omitempty"`
-	Description          string   `protobuf:"bytes,2,opt,name=description" json:"description,omitempty"`
-	TermsOfService       string   `protobuf:"bytes,3,opt,name=terms_of_service,json=termsOfService" json:"terms_of_service,omitempty"`
-	Contact              *Contact `protobuf:"bytes,4,opt,name=contact" json:"contact,omitempty"`
-	Version              string   `protobuf:"bytes,6,opt,name=version" json:"version,omitempty"`
+	Title                string   `protobuf:"bytes,1,opt,name=title,proto3" json:"title,omitempty"`
+	Description          string   `protobuf:"bytes,2,opt,name=description,proto3" json:"description,omitempty"`
+	TermsOfService       string   `protobuf:"bytes,3,opt,name=terms_of_service,json=termsOfService,proto3" json:"terms_of_service,omitempty"`
+	Contact              *Contact `protobuf:"bytes,4,opt,name=contact,proto3" json:"contact,omitempty"`
+	Version              string   `protobuf:"bytes,6,opt,name=version,proto3" json:"version,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
@@ -495,9 +495,9 @@ func (m *Info) GetVersion() string {
 //
 // TODO(ivucica): document fields
 type Contact struct {
-	Name                 string   `protobuf:"bytes,1,opt,name=name" json:"name,omitempty"`
-	Url                  string   `protobuf:"bytes,2,opt,name=url" json:"url,omitempty"`
-	Email                string   `protobuf:"bytes,3,opt,name=email" json:"email,omitempty"`
+	Name                 string   `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
+	Url                  string   `protobuf:"bytes,2,opt,name=url,proto3" json:"url,omitempty"`
+	Email                string   `protobuf:"bytes,3,opt,name=email,proto3" json:"email,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
@@ -555,8 +555,8 @@ func (m *Contact) GetEmail() string {
 //
 // TODO(ivucica): document fields
 type ExternalDocumentation struct {
-	Description          string   `protobuf:"bytes,1,opt,name=description" json:"description,omitempty"`
-	Url                  string   `protobuf:"bytes,2,opt,name=url" json:"url,omitempty"`
+	Description          string   `protobuf:"bytes,1,opt,name=description,proto3" json:"description,omitempty"`
+	Url                  string   `protobuf:"bytes,2,opt,name=url,proto3" json:"url,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
@@ -606,11 +606,11 @@ func (m *ExternalDocumentation) GetUrl() string {
 //
 // TODO(ivucica): document fields
 type Schema struct {
-	JsonSchema           *JSONSchema            `protobuf:"bytes,1,opt,name=json_schema,json=jsonSchema" json:"json_schema,omitempty"`
-	Discriminator        string                 `protobuf:"bytes,2,opt,name=discriminator" json:"discriminator,omitempty"`
-	ReadOnly             bool                   `protobuf:"varint,3,opt,name=read_only,json=readOnly" json:"read_only,omitempty"`
-	ExternalDocs         *ExternalDocumentation `protobuf:"bytes,5,opt,name=external_docs,json=externalDocs" json:"external_docs,omitempty"`
-	Example              *any.Any               `protobuf:"bytes,6,opt,name=example" json:"example,omitempty"`
+	JsonSchema           *JSONSchema            `protobuf:"bytes,1,opt,name=json_schema,json=jsonSchema,proto3" json:"json_schema,omitempty"`
+	Discriminator        string                 `protobuf:"bytes,2,opt,name=discriminator,proto3" json:"discriminator,omitempty"`
+	ReadOnly             bool                   `protobuf:"varint,3,opt,name=read_only,json=readOnly,proto3" json:"read_only,omitempty"`
+	ExternalDocs         *ExternalDocumentation `protobuf:"bytes,5,opt,name=external_docs,json=externalDocs,proto3" json:"external_docs,omitempty"`
+	Example              *any.Any               `protobuf:"bytes,6,opt,name=example,proto3" json:"example,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}               `json:"-"`
 	XXX_unrecognized     []byte                 `json:"-"`
 	XXX_sizecache        int32                  `json:"-"`
@@ -687,26 +687,26 @@ func (m *Schema) GetExample() *any.Any {
 //
 // TODO(ivucica): document fields
 type JSONSchema struct {
-	Title            string   `protobuf:"bytes,5,opt,name=title" json:"title,omitempty"`
-	Description      string   `protobuf:"bytes,6,opt,name=description" json:"description,omitempty"`
-	Default          string   `protobuf:"bytes,7,opt,name=default" json:"default,omitempty"`
-	MultipleOf       float64  `protobuf:"fixed64,10,opt,name=multiple_of,json=multipleOf" json:"multiple_of,omitempty"`
-	Maximum          float64  `protobuf:"fixed64,11,opt,name=maximum" json:"maximum,omitempty"`
-	ExclusiveMaximum bool     `protobuf:"varint,12,opt,name=exclusive_maximum,json=exclusiveMaximum" json:"exclusive_maximum,omitempty"`
-	Minimum          float64  `protobuf:"fixed64,13,opt,name=minimum" json:"minimum,omitempty"`
-	ExclusiveMinimum bool     `protobuf:"varint,14,opt,name=exclusive_minimum,json=exclusiveMinimum" json:"exclusive_minimum,omitempty"`
-	MaxLength        uint64   `protobuf:"varint,15,opt,name=max_length,json=maxLength" json:"max_length,omitempty"`
-	MinLength        uint64   `protobuf:"varint,16,opt,name=min_length,json=minLength" json:"min_length,omitempty"`
-	Pattern          string   `protobuf:"bytes,17,opt,name=pattern" json:"pattern,omitempty"`
-	MaxItems         uint64   `protobuf:"varint,20,opt,name=max_items,json=maxItems" json:"max_items,omitempty"`
-	MinItems         uint64   `protobuf:"varint,21,opt,name=min_items,json=minItems" json:"min_items,omitempty"`
-	UniqueItems      bool     `protobuf:"varint,22,opt,name=unique_items,json=uniqueItems" json:"unique_items,omitempty"`
-	MaxProperties    uint64   `protobuf:"varint,24,opt,name=max_properties,json=maxProperties" json:"max_properties,omitempty"`
-	MinProperties    uint64   `protobuf:"varint,25,opt,name=min_properties,json=minProperties" json:"min_properties,omitempty"`
-	Required         []string `protobuf:"bytes,26,rep,name=required" json:"required,omitempty"`
+	Title            string   `protobuf:"bytes,5,opt,name=title,proto3" json:"title,omitempty"`
+	Description      string   `protobuf:"bytes,6,opt,name=description,proto3" json:"description,omitempty"`
+	Default          string   `protobuf:"bytes,7,opt,name=default,proto3" json:"default,omitempty"`
+	MultipleOf       float64  `protobuf:"fixed64,10,opt,name=multiple_of,json=multipleOf,proto3" json:"multiple_of,omitempty"`
+	Maximum          float64  `protobuf:"fixed64,11,opt,name=maximum,proto3" json:"maximum,omitempty"`
+	ExclusiveMaximum bool     `protobuf:"varint,12,opt,name=exclusive_maximum,json=exclusiveMaximum,proto3" json:"exclusive_maximum,omitempty"`
+	Minimum          float64  `protobuf:"fixed64,13,opt,name=minimum,proto3" json:"minimum,omitempty"`
+	ExclusiveMinimum bool     `protobuf:"varint,14,opt,name=exclusive_minimum,json=exclusiveMinimum,proto3" json:"exclusive_minimum,omitempty"`
+	MaxLength        uint64   `protobuf:"varint,15,opt,name=max_length,json=maxLength,proto3" json:"max_length,omitempty"`
+	MinLength        uint64   `protobuf:"varint,16,opt,name=min_length,json=minLength,proto3" json:"min_length,omitempty"`
+	Pattern          string   `protobuf:"bytes,17,opt,name=pattern,proto3" json:"pattern,omitempty"`
+	MaxItems         uint64   `protobuf:"varint,20,opt,name=max_items,json=maxItems,proto3" json:"max_items,omitempty"`
+	MinItems         uint64   `protobuf:"varint,21,opt,name=min_items,json=minItems,proto3" json:"min_items,omitempty"`
+	UniqueItems      bool     `protobuf:"varint,22,opt,name=unique_items,json=uniqueItems,proto3" json:"unique_items,omitempty"`
+	MaxProperties    uint64   `protobuf:"varint,24,opt,name=max_properties,json=maxProperties,proto3" json:"max_properties,omitempty"`
+	MinProperties    uint64   `protobuf:"varint,25,opt,name=min_properties,json=minProperties,proto3" json:"min_properties,omitempty"`
+	Required         []string `protobuf:"bytes,26,rep,name=required,proto3" json:"required,omitempty"`
 	// Items in 'array' must be unique.
-	Array                []string                           `protobuf:"bytes,34,rep,name=array" json:"array,omitempty"`
-	Type                 []JSONSchema_JSONSchemaSimpleTypes `protobuf:"varint,35,rep,packed,name=type,enum=grpc.gateway.protoc_gen_swagger.options.JSONSchema_JSONSchemaSimpleTypes" json:"type,omitempty"`
+	Array                []string                           `protobuf:"bytes,34,rep,name=array,proto3" json:"array,omitempty"`
+	Type                 []JSONSchema_JSONSchemaSimpleTypes `protobuf:"varint,35,rep,packed,name=type,proto3,enum=grpc.gateway.protoc_gen_swagger.options.JSONSchema_JSONSchemaSimpleTypes" json:"type,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}                           `json:"-"`
 	XXX_unrecognized     []byte                             `json:"-"`
 	XXX_sizecache        int32                              `json:"-"`
@@ -877,8 +877,8 @@ func (m *JSONSchema) GetType() []JSONSchema_JSONSchemaSimpleTypes {
 type Tag struct {
 	// TODO(ivucica): Description should be extracted from comments on the proto
 	// service object.
-	Description          string                 `protobuf:"bytes,2,opt,name=description" json:"description,omitempty"`
-	ExternalDocs         *ExternalDocumentation `protobuf:"bytes,3,opt,name=external_docs,json=externalDocs" json:"external_docs,omitempty"`
+	Description          string                 `protobuf:"bytes,2,opt,name=description,proto3" json:"description,omitempty"`
+	ExternalDocs         *ExternalDocumentation `protobuf:"bytes,3,opt,name=external_docs,json=externalDocs,proto3" json:"external_docs,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}               `json:"-"`
 	XXX_unrecognized     []byte                 `json:"-"`
 	XXX_sizecache        int32                  `json:"-"`
@@ -932,7 +932,7 @@ func (m *Tag) GetExternalDocs() *ExternalDocumentation {
 // and only serves to provide the relevant details for each scheme.
 type SecurityDefinitions struct {
 	// A single security scheme definition, mapping a "name" to the scheme it defines.
-	Security             map[string]*SecurityScheme `protobuf:"bytes,1,rep,name=security" json:"security,omitempty" protobuf_key:"bytes,1,opt,name=key" protobuf_val:"bytes,2,opt,name=value"`
+	Security             map[string]*SecurityScheme `protobuf:"bytes,1,rep,name=security,proto3" json:"security,omitempty" protobuf_key:"bytes,1,opt,name=key,proto3" protobuf_val:"bytes,2,opt,name=value,proto3"`
 	XXX_NoUnkeyedLiteral struct{}                   `json:"-"`
 	XXX_unrecognized     []byte                     `json:"-"`
 	XXX_sizecache        int32                      `json:"-"`
@@ -981,36 +981,36 @@ func (m *SecurityDefinitions) GetSecurity() map[string]*SecurityScheme {
 type SecurityScheme struct {
 	// Required. The type of the security scheme. Valid values are "basic",
 	// "apiKey" or "oauth2".
-	Type SecurityScheme_Type `protobuf:"varint,1,opt,name=type,enum=grpc.gateway.protoc_gen_swagger.options.SecurityScheme_Type" json:"type,omitempty"`
+	Type SecurityScheme_Type `protobuf:"varint,1,opt,name=type,proto3,enum=grpc.gateway.protoc_gen_swagger.options.SecurityScheme_Type" json:"type,omitempty"`
 	// A short description for security scheme.
-	Description string `protobuf:"bytes,2,opt,name=description" json:"description,omitempty"`
+	Description string `protobuf:"bytes,2,opt,name=description,proto3" json:"description,omitempty"`
 	// Required. The name of the header or query parameter to be used.
 	//
 	// Valid for apiKey.
-	Name string `protobuf:"bytes,3,opt,name=name" json:"name,omitempty"`
+	Name string `protobuf:"bytes,3,opt,name=name,proto3" json:"name,omitempty"`
 	// Required. The location of the API key. Valid values are "query" or "header".
 	//
 	// Valid for apiKey.
-	In SecurityScheme_In `protobuf:"varint,4,opt,name=in,enum=grpc.gateway.protoc_gen_swagger.options.SecurityScheme_In" json:"in,omitempty"`
+	In SecurityScheme_In `protobuf:"varint,4,opt,name=in,proto3,enum=grpc.gateway.protoc_gen_swagger.options.SecurityScheme_In" json:"in,omitempty"`
 	// Required. The flow used by the OAuth2 security scheme. Valid values are
 	// "implicit", "password", "application" or "accessCode".
 	//
 	// Valid for oauth2.
-	Flow SecurityScheme_Flow `protobuf:"varint,5,opt,name=flow,enum=grpc.gateway.protoc_gen_swagger.options.SecurityScheme_Flow" json:"flow,omitempty"`
+	Flow SecurityScheme_Flow `protobuf:"varint,5,opt,name=flow,proto3,enum=grpc.gateway.protoc_gen_swagger.options.SecurityScheme_Flow" json:"flow,omitempty"`
 	// Required. The authorization URL to be used for this flow. This SHOULD be in
 	// the form of a URL.
 	//
 	// Valid for oauth2/implicit and oauth2/accessCode.
-	AuthorizationUrl string `protobuf:"bytes,6,opt,name=authorization_url,json=authorizationUrl" json:"authorization_url,omitempty"`
+	AuthorizationUrl string `protobuf:"bytes,6,opt,name=authorization_url,json=authorizationUrl,proto3" json:"authorization_url,omitempty"`
 	// Required. The token URL to be used for this flow. This SHOULD be in the
 	// form of a URL.
 	//
 	// Valid for oauth2/password, oauth2/application and oauth2/accessCode.
-	TokenUrl string `protobuf:"bytes,7,opt,name=token_url,json=tokenUrl" json:"token_url,omitempty"`
+	TokenUrl string `protobuf:"bytes,7,opt,name=token_url,json=tokenUrl,proto3" json:"token_url,omitempty"`
 	// Required. The available scopes for the OAuth2 security scheme.
 	//
 	// Valid for oauth2.
-	Scopes               *Scopes  `protobuf:"bytes,8,opt,name=scopes" json:"scopes,omitempty"`
+	Scopes               *Scopes  `protobuf:"bytes,8,opt,name=scopes,proto3" json:"scopes,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
@@ -1112,7 +1112,7 @@ type SecurityRequirement struct {
 	// the Security Definitions. If the security scheme is of type "oauth2",
 	// then the value is a list of scope names required for the execution.
 	// For other security scheme types, the array MUST be empty.
-	SecurityRequirement  map[string]*SecurityRequirement_SecurityRequirementValue `protobuf:"bytes,1,rep,name=security_requirement,json=securityRequirement" json:"security_requirement,omitempty" protobuf_key:"bytes,1,opt,name=key" protobuf_val:"bytes,2,opt,name=value"`
+	SecurityRequirement  map[string]*SecurityRequirement_SecurityRequirementValue `protobuf:"bytes,1,rep,name=security_requirement,json=securityRequirement,proto3" json:"security_requirement,omitempty" protobuf_key:"bytes,1,opt,name=key,proto3" protobuf_val:"bytes,2,opt,name=value,proto3"`
 	XXX_NoUnkeyedLiteral struct{}                                                 `json:"-"`
 	XXX_unrecognized     []byte                                                   `json:"-"`
 	XXX_sizecache        int32                                                    `json:"-"`
@@ -1153,7 +1153,7 @@ func (m *SecurityRequirement) GetSecurityRequirement() map[string]*SecurityRequi
 // scope names required for the execution. For other security scheme types,
 // the array MUST be empty.
 type SecurityRequirement_SecurityRequirementValue struct {
-	Scope                []string `protobuf:"bytes,1,rep,name=scope" json:"scope,omitempty"`
+	Scope                []string `protobuf:"bytes,1,rep,name=scope,proto3" json:"scope,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
 	XXX_unrecognized     []byte   `json:"-"`
 	XXX_sizecache        int32    `json:"-"`
@@ -1202,7 +1202,7 @@ func (m *SecurityRequirement_SecurityRequirementValue) GetScope() []string {
 type Scopes struct {
 	// Maps between a name of a scope to a short description of it (as the value
 	// of the property).
-	Scope                map[string]string `protobuf:"bytes,1,rep,name=scope" json:"scope,omitempty" protobuf_key:"bytes,1,opt,name=key" protobuf_val:"bytes,2,opt,name=value"`
+	Scope                map[string]string `protobuf:"bytes,1,rep,name=scope,proto3" json:"scope,omitempty" protobuf_key:"bytes,1,opt,name=key,proto3" protobuf_val:"bytes,2,opt,name=value,proto3"`
 	XXX_NoUnkeyedLiteral struct{}          `json:"-"`
 	XXX_unrecognized     []byte            `json:"-"`
 	XXX_sizecache        int32             `json:"-"`
diff --git a/runtime/BUILD.bazel b/runtime/BUILD.bazel
index e04db4f7096..9fce0447165 100644
--- a/runtime/BUILD.bazel
+++ b/runtime/BUILD.bazel
@@ -74,6 +74,7 @@ go_test(
         "@com_github_golang_protobuf//ptypes/timestamp:go_default_library",
         "@com_github_golang_protobuf//ptypes/wrappers:go_default_library",
         "@org_golang_google_genproto//protobuf/field_mask:go_default_library",
+        "@org_golang_google_genproto//googleapis/rpc/errdetails:go_default_library",
         "@org_golang_google_grpc//:go_default_library",
         "@org_golang_google_grpc//codes:go_default_library",
         "@org_golang_google_grpc//metadata:go_default_library",
diff --git a/runtime/errors.go b/runtime/errors.go
index 5cfedbf790a..d112dfb7e13 100644
--- a/runtime/errors.go
+++ b/runtime/errors.go
@@ -6,7 +6,6 @@ import (
 	"net/http"
 
 	"github.com/golang/protobuf/proto"
-	"github.com/golang/protobuf/ptypes"
 	"github.com/golang/protobuf/ptypes/any"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/grpclog"
@@ -94,19 +93,9 @@ func DefaultHTTPError(ctx context.Context, mux *ServeMux, marshaler Marshaler, w
 	}
 
 	body := &errorBody{
-		Error: s.Message(),
-		Code:  int32(s.Code()),
-	}
-
-	for _, detail := range s.Details() {
-		if det, ok := detail.(proto.Message); ok {
-			a, err := ptypes.MarshalAny(det)
-			if err != nil {
-				grpclog.Infof("Failed to marshal any: %v", err)
-			} else {
-				body.Details = append(body.Details, a)
-			}
-		}
+		Error:   s.Message(),
+		Code:    int32(s.Code()),
+		Details: s.Proto().GetDetails(),
 	}
 
 	buf, merr := marshaler.Marshal(body)
diff --git a/runtime/errors_test.go b/runtime/errors_test.go
index 2c7ecf18656..de51052893f 100644
--- a/runtime/errors_test.go
+++ b/runtime/errors_test.go
@@ -1,6 +1,7 @@
 package runtime_test
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
@@ -8,8 +9,8 @@ import (
 	"strings"
 	"testing"
 
-	"context"
 	"github.com/grpc-ecosystem/grpc-gateway/runtime"
+	"google.golang.org/genproto/googleapis/rpc/errdetails"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 )
@@ -17,10 +18,15 @@ import (
 func TestDefaultHTTPError(t *testing.T) {
 	ctx := context.Background()
 
+	statusWithDetails, _ := status.New(codes.FailedPrecondition, "failed precondition").WithDetails(
+		&errdetails.PreconditionFailure{},
+	)
+
 	for _, spec := range []struct {
-		err    error
-		status int
-		msg    string
+		err     error
+		status  int
+		msg     string
+		details string
 	}{
 		{
 			err:    fmt.Errorf("example error"),
@@ -32,10 +38,16 @@ func TestDefaultHTTPError(t *testing.T) {
 			status: http.StatusNotFound,
 			msg:    "no such resource",
 		},
+		{
+			err:     statusWithDetails.Err(),
+			status:  http.StatusPreconditionFailed,
+			msg:     "failed precondition",
+			details: "type.googleapis.com/google.rpc.PreconditionFailure",
+		},
 	} {
 		w := httptest.NewRecorder()
 		req, _ := http.NewRequest("", "", nil) // Pass in an empty request to match the signature
-		runtime.DefaultHTTPError(ctx, &runtime.ServeMux{}, &runtime.JSONBuiltin{}, w, req, spec.err)
+		runtime.DefaultHTTPError(ctx, &runtime.ServeMux{}, &runtime.JSONPb{}, w, req, spec.err)
 
 		if got, want := w.Header().Get("Content-Type"), "application/json"; got != want {
 			t.Errorf(`w.Header().Get("Content-Type") = %q; want %q; on spec.err=%v`, got, want, spec.err)
@@ -53,5 +65,20 @@ func TestDefaultHTTPError(t *testing.T) {
 		if got, want := body["error"].(string), spec.msg; !strings.Contains(got, want) {
 			t.Errorf(`body["error"] = %q; want %q; on spec.err=%v`, got, want, spec.err)
 		}
+
+		if spec.details != "" {
+			details, ok := body["details"].([]interface{})
+			if !ok {
+				t.Errorf(`body["details"] = %T; want %T`, body["details"], []interface{}{})
+				continue
+			}
+			if len(details) != 1 {
+				t.Errorf(`len(body["details"]) = %v; want 1`, len(details))
+				continue
+			}
+			if details[0].(map[string]interface{})["@type"] != spec.details {
+				t.Errorf(`details.@type = %s; want %s`, details[0].(map[string]interface{})["@type"], spec.details)
+			}
+		}
 	}
 }
diff --git a/runtime/internal/stream_chunk.pb.go b/runtime/internal/stream_chunk.pb.go
index a06c722c167..f4af074808b 100644
--- a/runtime/internal/stream_chunk.pb.go
+++ b/runtime/internal/stream_chunk.pb.go
@@ -22,11 +22,11 @@ const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
 // StreamError is a response type which is returned when
 // streaming rpc returns an error.
 type StreamError struct {
-	GrpcCode             int32      `protobuf:"varint,1,opt,name=grpc_code,json=grpcCode" json:"grpc_code,omitempty"`
-	HttpCode             int32      `protobuf:"varint,2,opt,name=http_code,json=httpCode" json:"http_code,omitempty"`
-	Message              string     `protobuf:"bytes,3,opt,name=message" json:"message,omitempty"`
-	HttpStatus           string     `protobuf:"bytes,4,opt,name=http_status,json=httpStatus" json:"http_status,omitempty"`
-	Details              []*any.Any `protobuf:"bytes,5,rep,name=details" json:"details,omitempty"`
+	GrpcCode             int32      `protobuf:"varint,1,opt,name=grpc_code,json=grpcCode,proto3" json:"grpc_code,omitempty"`
+	HttpCode             int32      `protobuf:"varint,2,opt,name=http_code,json=httpCode,proto3" json:"http_code,omitempty"`
+	Message              string     `protobuf:"bytes,3,opt,name=message,proto3" json:"message,omitempty"`
+	HttpStatus           string     `protobuf:"bytes,4,opt,name=http_status,json=httpStatus,proto3" json:"http_status,omitempty"`
+	Details              []*any.Any `protobuf:"bytes,5,rep,name=details,proto3" json:"details,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}   `json:"-"`
 	XXX_unrecognized     []byte     `json:"-"`
 	XXX_sizecache        int32      `json:"-"`