diff --git a/.github/workflows/docker-publish.yml b/.github/workflows/docker-publish.yml
index 2eed5942..e63475eb 100644
--- a/.github/workflows/docker-publish.yml
+++ b/.github/workflows/docker-publish.yml
@@ -20,16 +20,16 @@ jobs:
 
       - name: prepare tag 
         run: |
-            IMAGE_ID=jambonz/$IMAGE_NAME
+            export IMAGE_ID=jambonz/$IMAGE_NAME
 
             # Strip git ref prefix from version
-            VERSION=$(echo "${{ github.ref }}" | sed -e 's,.*/\(.*\),\1,')
+            export VERSION=$(echo "${{ github.ref }}" | sed -e 's,.*/\(.*\),\1,')
 
             # Strip "v" prefix from tag name
             [[ "${{ github.ref }}" == "refs/tags/"* ]] && VERSION=$(echo $VERSION | sed -e 's/^v//')
 
             # Use Docker `latest` tag convention
-            [ "$VERSION" == "main" ] && VERSION=latest
+            [ "$VERSION" == "main" ] && export VERSION=latest
 
             echo IMAGE_ID=$IMAGE_ID
             echo VERSION=$VERSION