diff --git a/README.md b/README.md
index e367db6..4025a97 100644
--- a/README.md
+++ b/README.md
@@ -235,6 +235,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
+      with:
+        # This may save additional git fetch roundtrip if
+        # merge-base is found within latest 20 commits
+        fetch-depth: 20
     - uses: dorny/paths-filter@v2
       id: filter
       with: