diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 0e350953..b1e1e3f4 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -23,7 +23,7 @@ jobs:
     - name: Set up Python 3.8
       uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: '3.8'
     - uses: pre-commit/action@v2.0.0
 
   tests:
@@ -31,7 +31,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [pypy-3.6, 3.6, 3.7, 3.8, 3.9]
+        python-version: ['pypy-3.6', '3.6', '3.7', '3.8', '3.9', '3.10']
 
     steps:
     - uses: actions/checkout@v2
@@ -45,9 +45,9 @@ jobs:
         pip install .[testing,linkify]
     - name: Run pytest
       run: |
-        pytest --cov=markdown_it --cov-report=xml --cov-report=term-missing
+        pytest tests/ --cov=markdown_it --cov-report=xml --cov-report=term-missing
     - name: Upload to Codecov
-      if: matrix.python-version == 3.7 && github.repository == 'executablebooks/markdown-it-py'
+      if: matrix.python-version == '3.7' && github.repository == 'executablebooks/markdown-it-py'
       uses: codecov/codecov-action@v1
       with:
         name: markdown-it-py-pytests-py3.7
@@ -60,7 +60,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8]
+        python-version: ['3.8']
     steps:
     - uses: actions/checkout@v2
     - name: Set up Python ${{ matrix.python-version }}
@@ -87,7 +87,7 @@ jobs:
     - name: Set up Python 3.8
       uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: '3.8'
 
     - name: Install tox
       run: |
@@ -116,7 +116,7 @@ jobs:
     - name: Set up Python 3.7
       uses: actions/setup-python@v2
       with:
-        python-version: 3.7
+        python-version: '3.7'
     - name: Build package
       run: |
         pip install wheel
diff --git a/setup.cfg b/setup.cfg
index f7647166..de38dd95 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -18,6 +18,7 @@ classifiers =
     Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
     Programming Language :: Python :: 3.9
+    Programming Language :: Python :: 3.10
     Programming Language :: Python :: Implementation :: CPython
     Programming Language :: Python :: Implementation :: PyPy
     Topic :: Software Development :: Libraries :: Python Modules
@@ -61,11 +62,13 @@ rtd =
     sphinx_book_theme
 testing =
     coverage
-    psutil
-    pytest>=3.6,<4
-    pytest-benchmark~=3.2
+    pytest
     pytest-cov
     pytest-regressions
+benchmarking =
+    psutil
+    pytest
+    pytest-benchmark~=3.2
 
 [options.packages.find]
 exclude =
diff --git a/tox.ini b/tox.ini
index 8b85b395..ff57b2a2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -9,13 +9,13 @@ envlist = py37
 [testenv]
 usedevelop = true
 
-[testenv:py{36,37,38,39}]
+[testenv:py{36,37,38,39,310}]
 extras =
     linkify
     testing
-commands = pytest {posargs}
+commands = pytest tests/ {posargs}
 
-[testenv:py{36,37,38,39}-plugins]
+[testenv:py{36,37,38,39,310}-plugins]
 extras = testing
 changedir = {envtmpdir}
 allowlist_externals =
@@ -28,11 +28,11 @@ commands =
     pytest {posargs}
 
 [testenv:py{36,37,38,39}-bench-core]
-extras = testing
+extras = benchmarking
 commands = pytest benchmarking/bench_core.py {posargs}
 
 [testenv:py{36,37,38}-bench-packages]
-extras = testing,compare
+extras = benchmarking,compare
 commands = pytest benchmarking/bench_packages.py {posargs}
 
 [testenv:docs-{update,clean}]