diff --git a/.mokogitea/workflows/pr-check.yml b/.mokogitea/workflows/pr-check.yml
index 35e2d5a..c834bf5 100644
--- a/.mokogitea/workflows/pr-check.yml
+++ b/.mokogitea/workflows/pr-check.yml
@@ -30,10 +30,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check branch merge target
-        env:
-          HEAD: ${{ github.head_ref }}
-          BASE: ${{ github.base_ref }}
         run: |
+          HEAD="${{ github.head_ref }}"
+          BASE="${{ github.base_ref }}"
 
           echo "PR: ${HEAD} → ${BASE}"