diff --git a/.github/workflows/format_and_lint_pr.yaml b/.github/workflows/format_and_lint_pr.yaml
index e3564e376..f0fe2b183 100644
--- a/.github/workflows/format_and_lint_pr.yaml
+++ b/.github/workflows/format_and_lint_pr.yaml
@@ -1,4 +1,4 @@
-name: Format and lint code
+name: Lint code
 on:
   pull_request:
 permissions:
@@ -15,5 +15,11 @@ jobs:
           python-version: '3.x'
       - name: Run Black
         uses: psf/black@stable
+        with:
+          options: "--check --diff -S"
+      - name: Install Flake8
+        run: |
+          python -m pip install --upgrade pip
+          pip install flake8
       - name: Run Flake8
         run: flake8 .
diff --git a/pelicun/tests/code_repetition_checker.py b/pelicun/tests/code_repetition_checker.py
index 3bf66f4f6..d4a02276f 100644
--- a/pelicun/tests/code_repetition_checker.py
+++ b/pelicun/tests/code_repetition_checker.py
@@ -80,6 +80,70 @@ def all_test_files():
     runs the main function to find and print repeated line blocks in each file.
     """
     test_files = glob('tests/*.py')
+    very_long_line = [
+        1.00,
+        2.00,
+        3.00,
+        4.00,
+        5.00,
+        6.00,
+        1.00,
+        2.00,
+        3.00,
+        4.00,
+        5.00,
+        6.00,
+        1.00,
+        2.00,
+        3.00,
+        4.00,
+        5.00,
+        6.00,
+        1.00,
+        2.00,
+        3.00,
+        4.00,
+        5.00,
+        6.00,
+        1.00,
+        2.00,
+        3.00,
+        4.00,
+        5.00,
+        6.00,
+        1.00,
+        2.00,
+        3.00,
+        4.00,
+        5.00,
+        6.00,
+        1.00,
+        2.00,
+        3.00,
+        4.00,
+        5.00,
+        6.00,
+        1.00,
+        2.00,
+        3.00,
+        4.00,
+        5.00,
+        6.00,
+    ]
+    very_long_string = (
+        'some very long thing which is some very '
+        'long thing which is some very long thing '
+        'which is some very long thing which is '
+        'some very long thing which is some very '
+        'long thing which is some very long thing '
+        'which is some very long thing which is '
+        'some very long thing which is some very '
+        'long thing which is some very long thing '
+        'which is some very long thing which is '
+        'very long indeed.'
+    )
+    assert very_long_line is not None
+    assert very_long_string is not None
     for file in test_files:
         print()
         print(file)