diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 164aeaf79f3d..ff94b54ab646 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -88,13 +88,18 @@ jobs:
   pyright:
     name: Run pyright against the stubs
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-platform: ["Linux", "Windows", "Darwin"]
+        python-version: [3.6, 3.7, 3.8, 3.9]
+      fail-fast: false
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v2
       - uses: actions/setup-node@v2
         with:
           node-version: '14'
-      - run: ./tests/pyright_test.py
+      - run: ./tests/pyright_test.py --pythonplatform ${{ matrix.python-platform }} --pythonversion ${{ matrix.python-version }}
 
   stubtest:
     name: Check stdlib with stubtest
diff --git a/pyrightconfig.json b/pyrightconfig.json
index 1ffb8c0beaee..bbb3168a8193 100644
--- a/pyrightconfig.json
+++ b/pyrightconfig.json
@@ -39,7 +39,6 @@
         "stubs/waitress",
         "stubs/Werkzeug"
     ],
-    "pythonVersion": "3.9",
     "typeCheckingMode": "basic",
     "strictListInference": true,
     "strictDictionaryInference": true,
diff --git a/tests/pyright_test.py b/tests/pyright_test.py
index 926fb952da45..2d4f0a8e6ff3 100755
--- a/tests/pyright_test.py
+++ b/tests/pyright_test.py
@@ -1,30 +1,37 @@
 #!/usr/bin/env python3
 
+import shutil
 import subprocess
 import sys
 from pathlib import Path
 
-
+_PYRIGHT_VERSION = "1.1.115"
 _WELL_KNOWN_FILE = Path("tests", "pyright_test.py")
-_PYRIGHT_COMMAND = ["npx", "-p", "pyright@1.1.114", "pyright"]
 
 
 def main() -> None:
-    assert_npm_is_installed()
-    ret = subprocess.run(_PYRIGHT_COMMAND).returncode
-    sys.exit(ret)
-
-
-def assert_npm_is_installed() -> None:
     if not _WELL_KNOWN_FILE.exists():
         print("pyright_test.py must be run from the typeshed root directory", file=sys.stderr)
         sys.exit(1)
+
+    # subprocess.run on Windows does not look in PATH.
+    npx = shutil.which("npx")
+
+    if npx is None:
+        print("error finding npx; is Node.js installed?", file=sys.stderr)
+        sys.exit(1)
+
     try:
-        subprocess.run(["npx", "--version"])
+        subprocess.run([npx, "--version"])
     except OSError:
         print("error running npx; is Node.js installed?", file=sys.stderr)
         sys.exit(1)
 
+    command = [npx, "-p", "pyright@" + _PYRIGHT_VERSION, "pyright"] + sys.argv[1:]
+
+    ret = subprocess.run(command).returncode
+    sys.exit(ret)
+
 
 if __name__ == "__main__":
     main()