diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 0737586..1229614 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -1,4 +1,4 @@
-name: CI of hpipm-cpp
+name: CI
 
 on:
   push:
@@ -16,7 +16,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-20.04, ubuntu-18.04]
+        os: [ubuntu-22.04, ubuntu-20.04, ubuntu-18.04]
         build-type: [Debug, RelWithDebInfo, Release]
     runs-on: ${{ matrix.os }}
     steps:
diff --git a/README.md b/README.md
index 3b4ef0a..6d15dea 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,5 @@
 # hpipm-cpp: A C++ wrapper for [hpipm](https://github.com/giaf/hpipm)
+[![CI](https://github.com/mayataka/hpipm-cpp/actions/workflows/ci.yaml/badge.svg)](https://github.com/mayataka/hpipm-cpp/actions/workflows/ci.yaml)
 
 A C++ wrapper for [hpipm](https://github.com/giaf/hpipm), a high-performance interior-point method (IPM) solver for structured quadratic programming (QP) arising in optimal control (OC) and model predictive control (MPC).
 This wrapper provides an interface of hpipm using STL and Eigen and inspired by [control-toolbox](https://github.com/ethz-adrl/control-toolbox) and [ocs2](https://github.com/leggedrobotics/ocs2).