diff --git a/.github/workflows/darker.yml b/.github/workflows/darker.yml
index c62d4a25..4a0a00ef 100644
--- a/.github/workflows/darker.yml
+++ b/.github/workflows/darker.yml
@@ -11,8 +11,6 @@ jobs:
           fetch-depth: 0
       - name: "create-main-branch"
         run: "git branch --track main origin/main"
-      - name: "get-merge-base"
-        run: "base_commit=$(git merge-base main HEAD)"
       - uses: actions/setup-python@v4
       - uses: akaihola/darker@1.7.0
         with:
@@ -20,4 +18,4 @@ jobs:
           src: "."
           version: "~=1.7.0"
           lint: "flake8,pylint==2.13.1"
-          revision: "$base_commit...HEAD"
+          revision: "origin/main..."