diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 157da0d6b..5a788010e 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -138,7 +138,7 @@ jobs:
       - name: Relative diff
         run: |
           git branch -av
-          git diff origin/${{ github.base_ref }}.. | tee git.diff
+          git diff origin/${{ github.base_ref }}.. -- '*.rs' | tee git.diff
       - uses: taiki-e/install-action@v2
         with:
           tool: cargo-mutants@25.2.2