diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 13c8e40..b4e8167 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -41,8 +41,15 @@ jobs:
           deno-version: ${{ env.DENO_VERSION }}
       - name: Test
         run: |
-          deno task test
+          deno task test:coverage
         timeout-minutes: 5
+      - run: |
+          deno task coverage --lcov > coverage.lcov
+      - uses: codecov/codecov-action@v4
+        with:
+          os: ${{ runner.os }}
+          files: ./coverage.lcov
+          token: ${{ secrets.CODECOV_TOKEN }}
 
   build-npm:
     runs-on: ubuntu-latest
diff --git a/README.md b/README.md
index 2a41ecf..1c8628d 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,7 @@
 [![deno doc](https://doc.deno.land/badge.svg)](https://doc.deno.land/https/deno.land/x/errorutil/mod.ts)
 [![Test](https://github.com/lambdalisue/deno-errorutil/workflows/Test/badge.svg)](https://github.com/lambdalisue/deno-errorutil/actions?query=workflow%3ATest)
 [![npm version](https://badge.fury.io/js/@lambdalisue%2Ferrorutil.svg)](https://badge.fury.io/js/@lambdalisue%2Ferrorutil)
+[![codecov](https://codecov.io/gh/lambdalisue/deno-errorutil/graph/badge.svg?token=O0cA5Xj5la)](https://codecov.io/gh/lambdalisue/deno-errorutil)
 
 A utility pack for handling error.