diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..c43bdb2
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,4 @@
+# Container image that runs your code
+FROM ghcr.io/unidata/thredds-test-action:v2
+USER root
+ENV GITHUB_ACTIONS="YEP"
diff --git a/action.yml b/action.yml
index 1361525..94ee2ce 100644
--- a/action.yml
+++ b/action.yml
@@ -16,7 +16,7 @@ inputs:
     required: true
 runs:
   using: 'docker'
-  image: 'ghcr.io/unidata/thredds-test-action:v2'
+  image: 'Dockerfile'
   args:
     - ${{ inputs.java-vendor}}
     - ${{ inputs.java-version }}