[tox]
 envlist =
     clean,
-    py{27,35,36,37,38},
+    py{37,38,39,310,311},
     stats
 
 [testenv]
 deps =
-    nose
     coverage
 passenv = HOME  ; Needed to find locally installed fonts when testing PDF production.
+download = true
 commands =
-    nosetests --with-coverage --cover-package=librarian -d --with-doctest --with-xunit --exe
-install_command = pip install --extra-index-url https://py.mdrn.pl/simple {packages}
+    coverage run
+install_command = pip install numpy; pip install --extra-index-url https://py.mdrn.pl/simple {packages}
 
 [testenv:clean]
 basepython = python3
 [testenv:stats]
 basepython = python3
 commands =
+    coverage combine
     coverage report
     coverage html
 deps = coverage
 
+[coverage:run]
+parallel = True
+source_pkgs = librarian
+command_line = -m unittest
+
+[coverage:paths]
+source = src/
+    .tox/*/lib/*/site-packages/
+