diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 1a94a6b3..1db462a4 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -59,7 +59,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: [deploy]
     if: |
-      !(contains(github.ref, "a") || contains(github.ref, "b"))
+      !(contains(github.ref, 'a') || contains(github.ref, 'b'))
     steps:
     - uses: actions/checkout@v2
     - name: Build and push to Docker Hub