diff --git a/.travis.yml b/.travis.yml
index d08beec47009613b49a25b2418dc10e84eb5b274..167375c335686388b4465a7945b0e86c11eb68f4 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -18,7 +18,7 @@ before_install:
   - conda info -a
 install:
   - conda config --add channels conda-forge
-  - conda create -q -n test-environment python=$TRAVIS_PYTHON_VERSION obspy pycurl pytest pytest-cov webtest
+  - conda create -q -n test-environment python=$TRAVIS_PYTHON_VERSION obspy pycurl flake8 pytest pytest-cov webtest
   - source activate test-environment
   - pip install authlib flask flask-login flask-migrate flask-session flask-sqlalchemy psycopg2-binary
 script: