diff --git a/README.md b/README.md
index 4d3dacd..a6ee32e 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Tomcat
 
-[![npm](https://img.shields.io/npm/v/@tomrpc/core.svg)](https://www.npmjs.com/package/@tomrpc/core)  [![Node.js CI](https://github.com/npmstudy/tomcat/actions/workflows/ci.yml/badge.svg)](https://github.com/npmstudy/tomcat/actions/workflows/ci.yml)
+[![npm](https://img.shields.io/npm/v/@tomrpc/core.svg)](https://www.npmjs.com/package/@tomrpc/core)  [![Node.js CI](https://github.com/npmstudy/tomcat/actions/workflows/ci.yml/badge.svg)](https://github.com/npmstudy/tomcat/actions/workflows/ci.yml) [![codecov](https://codecov.io/gh/npmstudy/tomcat/graph/badge.svg?token=JKAAY92RBH)](https://codecov.io/gh/npmstudy/tomcat)
 
 > Build function-based API with minimal code