diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index c4c13ce5..c82bc701 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -70,6 +70,7 @@ jobs:
         with:
           githubToken: ${{ secrets.GITHUB_TOKEN }}
           prefix: "jupyterhub/configurable-http-proxy:"
+          defaultTag: jupyterhub/configurable-http-proxy:noref
 
       - name: Display tags
         run: echo "Docker tags ${{ steps.gettags.outputs.tags }}"
diff --git a/Dockerfile b/Dockerfile
index c800dfa5..a7c60510 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
-FROM node:lts-alpine3.12
-# ref: https://hub.docker.com/_/node?tab=tags&name=12
+FROM node:lts-alpine3.15
+# ref: https://hub.docker.com/_/node?tab=tags&name=lts-alpine
 
 LABEL maintainer="Jupyter Project <jupyter@googlegroups.com>"