diff --git a/.github/workflows/ci-build.yml b/.github/workflows/ci-build.yml
index 44463ccb3..5b0bc0484 100644
--- a/.github/workflows/ci-build.yml
+++ b/.github/workflows/ci-build.yml
@@ -13,7 +13,7 @@ jobs:
     timeout-minutes: 15
     strategy:
       matrix:
-        python-version: ['3.6', '3.7', '3.8', '3.9']
+        python-version: ['3.6', '3.7', '3.8', '3.9', '3.10']
     env:
       # default: multiprocessing
       # threading is more stable on GitHub Actions
@@ -28,7 +28,7 @@ jobs:
       run: |
         python setup.py install
         pip install -U pip
-        pip install "pytest>=5,<6" "pytest-cov>=2,<3" "flask_sockets>0.2,<1"
+        pip install -e ".[testing_without_asyncio]"
     - name: Run tests without aiohttp
       run: |
         pytest tests/slack_bolt/
diff --git a/setup.py b/setup.py
index 8d5e65851..0ea7278ee 100755
--- a/setup.py
+++ b/setup.py
@@ -13,15 +13,18 @@
     long_description = fh.read()
 
 test_dependencies = [
-    "pytest>=5,<6",
+    "pytest>=6.2.5,<7",
     "pytest-cov>=2,<3",
-    "pytest-asyncio<1",  # for async
-    "aiohttp>=3,<4",  # for async
     "Flask-Sockets>=0.2,<1",
     "Werkzeug<2",  # TODO: support Flask 2.x
     "black==21.9b0",
 ]
 
+async_test_dependencies = test_dependencies + [
+    "pytest-asyncio<1",  # for async
+    "aiohttp>=3,<4",  # for async
+]
+
 setuptools.setup(
     name="slack_bolt",
     version=__version__,
@@ -45,7 +48,7 @@
         "slack_sdk>=3.9.0,<4",
     ],
     setup_requires=["pytest-runner==5.2"],
-    tests_require=test_dependencies,
+    tests_require=async_test_dependencies,
     test_suite="tests",
     extras_require={
         # pip install -e ".[async]"
@@ -84,14 +87,17 @@
             # Socket Mode 3rd party implementation
             "websocket_client>=1,<2",
         ],
+        # pip install -e ".[testing_without_asyncio]"
+        "testing_without_asyncio": test_dependencies,
         # pip install -e ".[testing]"
-        "testing": test_dependencies,
+        "testing": async_test_dependencies,
     },
     classifiers=[
         "Programming Language :: Python :: 3.6",
         "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",
         "License :: OSI Approved :: MIT License",
         "Operating System :: OS Independent",