diff --git a/.github/workflows/build-image.yaml b/.github/workflows/build-image.yaml
index c6916e05..5103f3a4 100644
--- a/.github/workflows/build-image.yaml
+++ b/.github/workflows/build-image.yaml
@@ -96,7 +96,7 @@ jobs:
       - name: Determine Image Tags
         id: determine-image-tags
         run: |
-          buildType = ${{ env.BUILD_TYPE }}
+          buildType="${{ env.BUILD_TYPE }}"
 
           case $buildType in
             "build_only" | "build_push_pycsw")