diff --git a/protoc-gen-go-jsonpb/main.go b/protoc-gen-go-jsonpb/main.go
index efb5489..912e55a 100644
--- a/protoc-gen-go-jsonpb/main.go
+++ b/protoc-gen-go-jsonpb/main.go
@@ -85,7 +85,16 @@ func main() {
 
 func generate(req *plugin.CodeGeneratorRequest) ([]*plugin.CodeGeneratorResponse_File, error) {
 	var files []*plugin.CodeGeneratorResponse_File
+	genFileNames := make(map[string]bool)
+	for _, n := range req.FileToGenerate {
+		genFileNames[n] = true
+	}
 	for _, desc := range req.GetProtoFile() {
+		name := desc.GetName()
+		if _, ok := genFileNames[name]; !ok {
+			// Only emit output for files present in req.FileToGenerate.
+			continue
+		}
 		code, err := genCode(desc)
 		if err != nil {
 			return nil, err
@@ -96,7 +105,6 @@ func generate(req *plugin.CodeGeneratorRequest) ([]*plugin.CodeGeneratorResponse
 			return nil, err
 		}
 
-		name := desc.GetName()
 		ext := filepath.Ext(name)
 		base := strings.TrimSuffix(name, ext)
 		output := fmt.Sprintf("%s.pb.jsonpb.go", base)