diff --git a/persister.go b/persister.go
index 3336f70..5cbcece 100644
--- a/persister.go
+++ b/persister.go
@@ -8,6 +8,7 @@ import (
 	"github.com/golang/protobuf/proto"
 	plugin_go "github.com/golang/protobuf/protoc-gen-go/plugin"
 	"github.com/spf13/afero"
+	"google.golang.org/protobuf/types/pluginpb"
 )
 
 type persister interface {
@@ -33,6 +34,9 @@ func (p *stdPersister) AddPostProcessor(proc ...PostProcessor) { p.procs = appen
 func (p *stdPersister) Persist(arts ...Artifact) *plugin_go.CodeGeneratorResponse {
 	resp := new(plugin_go.CodeGeneratorResponse)
 
+	supportedFeatures := uint64(pluginpb.CodeGeneratorResponse_FEATURE_PROTO3_OPTIONAL)
+	resp.SupportedFeatures = &supportedFeatures
+
 	for _, a := range arts {
 		switch a := a.(type) {
 		case GeneratorFile: