diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index cf459a8..4c36d7d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,7 +12,8 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        python-version: ['3.7', '3.8', '3.9', '3.10']  # 'pypy-3.7'
+        python-version: ['3.7', '3.8', '3.9', '3.10']
+
     steps:
       - uses: actions/checkout@v3
       - name: Setup Python
@@ -25,6 +26,24 @@ jobs:
       - run: make test
       - run: make lint
 
+  build_and_test_pypy:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        python-version: ['pypy-3.7']
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Setup Python
+        uses: actions/setup-python@v3
+        with:
+          python-version: ${{ matrix.python-version }}
+          cache: 'pip'
+          cache-dependency-path: 'requirements-min.txt'
+      - run: pip install . -r requirements-min.txt
+      - run: make test
+
   build_and_test_latest:
     runs-on: ${{ matrix.os }}
     strategy:
diff --git a/requirements-min.txt b/requirements-min.txt
index 85db5b2..cacc241 100644
--- a/requirements-min.txt
+++ b/requirements-min.txt
@@ -1,114 +1,105 @@
 #
-# This file is autogenerated by pip-compile with python 3.6
-# To update, run:
+# This file is autogenerated by pip-compile with Python 3.7
+# by the following command:
 #
 #    pip-compile --output-file=requirements-dev.txt requirements-dev.in setup.py
 #
 async-generator==1.10
     # via
-    #   pytest-trio
     #   trio
     #   trio-websocket (setup.py)
-attrs==21.4.0
+attrs==22.2.0
     # via
     #   -r requirements-dev.in
     #   outcome
     #   pytest
     #   trio
-certifi==2021.10.8
+build==0.10.0
+    # via pip-tools
+certifi==2022.12.7
     # via requests
-cffi==1.15.0
+cffi==1.15.1
     # via cryptography
-charset-normalizer==2.0.10
+charset-normalizer==3.1.0
     # via requests
-click==8.0.3
+click==8.1.3
     # via pip-tools
-contextvars==2.4
-    # via
-    #   sniffio
-    #   trio
-coverage[toml]==6.2
+coverage[toml]==6.5.0
     # via
     #   pytest-cov
-cryptography==3.3.2
+cryptography==39.0.2
     # via trustme
-dataclasses==0.8
-    # via wsproto
-h11==0.12.0
+exceptiongroup==1.1.0
+    # via
+    #   pytest
+    #   trio
+h11==0.14.0
     # via wsproto
-idna==3.3
+idna==3.4
     # via
     #   requests
     #   trio
     #   trustme
-immutables==0.16
-    # via contextvars
-importlib-metadata==4.8.3
-    # via
-    #   click
-    #   pep517
-    #   pluggy
-    #   pytest
-iniconfig==1.1.1
+importlib-resources==5.12.0
+    # via keyring
+iniconfig==2.0.0
     # via pytest
-outcome==1.1.0
+outcome==1.2.0
     # via
     #   pytest-trio
     #   trio
-packaging==21.3
-    # via pytest
-pep517==0.12.0
-    # via pip-tools
-pip-tools==6.4.0
+packaging==23.0
+    # via
+    #   build
+    #   pytest
+pip-tools==6.12.3
     # via -r requirements-dev.in
 pluggy==1.0.0
     # via pytest
-py==1.11.0
-    # via pytest
 pycparser==2.21
     # via cffi
-pyparsing==3.0.6
-    # via packaging
-pytest==6.2.5
+pyproject-hooks==1.0.0
+    # via build
+pytest==7.2.2
     # via
     #   -r requirements-dev.in
     #   pytest-cov
     #   pytest-trio
-pytest-cov==3.0.0
+pytest-cov==4.0.0
     # via -r requirements-dev.in
-pytest-trio==0.7.0
+pytest-trio==0.8.0
     # via -r requirements-dev.in
-sniffio==1.2.0
+pytz==2022.7.1
+    # via babel
+sniffio==1.3.0
     # via trio
 sortedcontainers==2.4.0
     # via trio
-toml==0.10.2
-    # via pytest
-tomli==1.2.3
+tomli==2.0.1
     # via
+    #   build
     #   coverage
-    #   pep517
-trio==0.19.0
+    #   pyproject-hooks
+    #   pytest
+trio==0.22.0
     # via
     #   -r requirements-dev.in
     #   pytest-trio
     #   trio-websocket (setup.py)
 trustme==0.9.0
     # via -r requirements-dev.in
-typing-extensions==4.0.1
+typing-extensions==4.5.0
     # via
-    #   immutables
-    #   importlib-metadata
-urllib3==1.26.8
-    # via requests
-wheel==0.37.1
+    #   h11
+    #   platformdirs
+wheel==0.38.4
     # via pip-tools
-wsproto==0.15.0
+wsproto==1.2.0
     # via trio-websocket (setup.py)
-zipp==3.6.0
+zipp==3.15.0
     # via
     #   importlib-metadata
-    #   pep517
+    #   importlib-resources
 
 # The following packages are considered to be unsafe in a requirements file:
 # pip