diff --git a/.github/workflows/webhook.yml b/.github/workflows/webhook.yml
index 92915f9..f114c66 100644
--- a/.github/workflows/webhook.yml
+++ b/.github/workflows/webhook.yml
@@ -66,7 +66,7 @@ jobs:
 #        name: confirm image is not already pushed
 
       - run: |
-          TAG_NAME=$TAG_PREFIX:v${{ steps.version-selector.outputs.VERSION }}
+          TAG_NAME=${{ env.TAG_PREFIX }}:v${{ steps.version-selector.outputs.VERSION }}
           git rev-parse -q --verify "refs/tags/$TAG_NAME"
         name: confirm git tag does not exist