diff --git a/.github/workflows/flake8.yml b/.github/workflows/flake8.yml
index efb81565..3b067cd2 100644
--- a/.github/workflows/flake8.yml
+++ b/.github/workflows/flake8.yml
@@ -21,6 +21,6 @@ jobs:
       - name: flake8 Lint
         uses: py-actions/flake8@v1
         with:
-          ignore: "E501"
+          ignore: "E501,W605"
           exclude: "__init__.py, input/__init__.py"
           path: "pyerrors"
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index cd627bd2..8ef8055e 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -24,12 +24,12 @@ For all pull requests tests are executed for the most recent python releases via
 ```
 pytest --cov=pyerrors -vv
 ```
-requiring `pytest`, `pytest-cov` and `pytest-benchmark`. To get a coverage report in html run 
+requiring `pytest`, `pytest-cov` and `pytest-benchmark`. To get a coverage report in html run
 ```
 pytest --cov=pyerrors --cov-report html
 ```
 The linter `flake8` is executed with the command
 ```
-flake8 --ignore=E501 --exclude=__init__.py pyerrors
+flake8 --ignore=E501,W605 --exclude=__init__.py pyerrors
 ```
 Please make sure that all tests are passed for a new pull requests.