diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index eff288b..f3691ff 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -52,7 +52,7 @@ jobs:
       - id: get-versions
         # TODO paging
         run: |
-          URL=https://hub.docker.com/v2/repositories/vulhub/java/tags/?page_size=100
+          URL="https://hub.docker.com/v2/repositories/vulhub/java/tags/?page_size=100"
           VERSIONS=$((curl -s $URL && curl -s "$URL&page=2") | jq -rc '[[.results[].name] | _nwise(3) | join(" ")]')
           echo "::set-output name=versions::$VERSIONS"