diff --git a/Dockerfile b/Dockerfile
index 96b8101..0539bdd 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM codex:latest
+FROM gitea.jsc.idv.tw/images/codex:$CODEX_VERSION
 
 RUN apt update \
   && apt install -y --no-install-recommends git
diff --git a/action.yaml b/action.yaml
index f5876e4..f10123e 100644
--- a/action.yaml
+++ b/action.yaml
@@ -15,6 +15,7 @@ runs:
   using: 'docker'
   image: 'Dockerfile'
   env:
+    CODEX_VERSION: ${{ vars.IMAGE_CODEX_VERSION }}
     GITEA_SERVER_URL: ${{ gitea.server_url }}
     GITEA_REPOSITORY: ${{ gitea.repository }}
     GITEA_TOKEN: ${{ inputs.token || gitea.token }}