diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index bff5f91..60866b8 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -33,3 +33,13 @@ jobs:
       run: cargo build --release --verbose
     - name: Run tests
       run: cargo test --verbose
+    - name: TDD check old tests
+      run: |
+        first_commit_hash=$(git rev-list --max-parents=0 HEAD)
+        first_commit_message=$(git log -1 --pretty=%B $first_commit_hash)
+        case $first_commit_message in
+          fix*|feat*|bug*)
+            git checkout $first_commit_hash~1 -- tests
+            !cargo test --verbose
+            ;;
+        esac