diff --git a/.travis.yml b/.travis.yml
index 9f84fc9..a03b5d2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,7 +5,7 @@ matrix:
     # Full tests (with online API)
     - os: linux
       language: python
-      python: 3.7
+      python: 3.9
       dist: xenial
       sudo: true
       env:
@@ -23,25 +23,27 @@ matrix:
     # Mock tests (with mock API)
     - os: linux
       language: python
-      python: 3.5
+      python: 3.6
       env:
         - TO_TEST=TEST_MOCK
     - os: linux
       language: python
-      python: 3.6
+      dist: xenial
+      python: 3.7
+      sudo: true
       env:
         - TO_TEST=TEST_MOCK
     - os: linux
       language: python
       dist: xenial
-      python: 3.7
+      python: 3.8
       sudo: true
       env:
         - TO_TEST=TEST_MOCK
     - os: linux
       language: python
       dist: xenial
-      python: 3.8
+      python: 3.9
       sudo: true
       env:
         - TO_TEST=TEST_MOCK
@@ -58,7 +60,7 @@ matrix:
       language: python
       dist: xenial
       sudo: true
-      python: 3.8
+      python: 3.9
       env:
         - TO_TEST=INSTALL
       if: type = cron
diff --git a/dev_requirements.txt b/dev_requirements.txt
index f6555a6..b9879c5 100644
--- a/dev_requirements.txt
+++ b/dev_requirements.txt
@@ -24,4 +24,4 @@ certifi
 #        (also remove in setup.py)
 ddt==1.3.1
 mock
-pytest # optional (python setup.py test works without it), but possible nonetheless
+pytest
diff --git a/setup.py b/setup.py
index a8eb7de..f5e45d2 100644
--- a/setup.py
+++ b/setup.py
@@ -45,23 +45,22 @@ setup(
         },
 
     include_package_data=True,
-
     install_requires=['pyyaml', 'bibtexparser>=1.0', 'python-dateutil', 'six',
                       'requests', 'configobj', 'beautifulsoup4', 'feedparser'],
     extras_require={'autocompletion': ['argcomplete'],
                     },
 
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 4 - Beta',
         'License :: OSI Approved :: GNU Lesser General Public License v3 (LGPLv3)',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Intended Audience :: Developers',
         'Intended Audience :: Science/Research',
     ],
 
     test_suite='tests',
-    tests_require=['pyfakefs>=3.4', 'mock', 'ddt==1.3.1', 'certifi'],
+    tests_require=['pyfakefs>=3.4', 'mock', 'ddt==1.3.1', 'certifi', 'pytest'],
 
     # in order to avoid 'zipimport.ZipImportError: bad local file header'
     zip_safe=False,