diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d182df4..8434adc 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -170,8 +170,6 @@ jobs:
       group: ${{ github.event_name }}-${{ github.workflow }}-${{ github.ref_name }}-run-sample
       cancel-in-progress: true
     timeout-minutes: 20
-    container:
-      image: ghcr.io/thombashi/python-ci:3.11
 
     steps:
       - uses: actions/checkout@v4