diff --git a/post_processor/post_processor.h b/post_processor/post_processor.h
index ffba3d3..c8d3a78 100644
--- a/post_processor/post_processor.h
+++ b/post_processor/post_processor.h
@@ -64,6 +64,7 @@ class PostProcessor {
   void InitITNResource(const std::string& tagger_path,
                        const std::string& verbalizer_path);
   private:
+    std::shared_ptr<PostProcessor> itn_resource = nullptr;
     const PostProcessOptions opts_;
   public:
   WENET_DISALLOW_COPY_AND_ASSIGN(PostProcessor);