diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6258063d..a8357f3e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,6 +11,9 @@ on:
     branches:
       - main
 
+env:
+  MAIN_BRANCH: ${{ 'refs/heads/main' }}
+
 jobs:
   check_nix:
     name: Basic Check
@@ -75,7 +78,7 @@ jobs:
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
       - name: Publish images
-        if: github.ref == 'refs/heads/main'
+        if: github.ref == env.MAIN_BRANCH
         run: |
           nix run ./#publish-kardinal-manager-container
           nix run ./#publish-kardinal-cli-container