diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index f99e55d27de2..8ba682c0bd66 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -76,11 +76,20 @@ jobs:
         python-platform: ["Linux", "Windows", "Darwin"]
         python-version: [3.6, 3.7, 3.8, 3.9, '3.10']
       fail-fast: false
+    env:
+      PYRIGHT_VERSION: 1.1.148  # Must match pyright_test.py.
     steps:
       - uses: actions/checkout@v2
       - uses: jakebailey/pyright-action@v1
         with:
-          version: 1.1.144  # Must match pyright_test.py.
+          version: ${{ env.PYRIGHT_VERSION }}
+          python-platform: ${{ matrix.python-platform }}
+          python-version: ${{ matrix.python-version }}
+          no-comments: ${{ matrix.python-version != '3.9' || matrix.python-platform != 'Linux' }}  # Having each job create the same comment is too noisy.
+          project: ./pyrightconfig.stricter.json
+      - uses: jakebailey/pyright-action@v1
+        with:
+          version: ${{ env.PYRIGHT_VERSION }}
           python-platform: ${{ matrix.python-platform }}
           python-version: ${{ matrix.python-version }}
           no-comments: ${{ matrix.python-version != '3.9' || matrix.python-platform != 'Linux' }}  # Having each job create the same comment is too noisy.
diff --git a/pyrightconfig.json b/pyrightconfig.json
index b1163e35399c..fcdeaf92bf5e 100644
--- a/pyrightconfig.json
+++ b/pyrightconfig.json
@@ -56,7 +56,7 @@
     "reportInvalidTypeVarUse": "error",
     "reportPropertyTypeMismatch": "error",
     "reportSelfClsParameterName": "error",
-    // Overloapping overloads cannot be enabled at this time because
+    // Overlapping overloads cannot be enabled at this time because
     // of the "factions.Fraction.__pow__" method and "tasks.gather" function.
     // Mypy's overlapping overload logic misses these issues (see mypy
     // issue #10143 and #10157).
diff --git a/pyrightconfig.stricter.json b/pyrightconfig.stricter.json
new file mode 100644
index 000000000000..4d84e8dfe92f
--- /dev/null
+++ b/pyrightconfig.stricter.json
@@ -0,0 +1,93 @@
+{
+    "$schema": "https://raw.githubusercontent.com/microsoft/pyright/main/packages/vscode-pyright/schemas/pyrightconfig.schema.json",
+    "typeshedPath": ".",
+    "include": [
+        "stdlib",
+        "stubs"
+    ],
+    "exclude": [
+        // Python 2 only modules.
+        "**/@python2",
+        "stubs/enum34",
+        "stubs/fb303",
+        "stubs/futures",
+        "stubs/ipaddress",
+        "stubs/kazoo",
+        "stubs/openssl-python",
+        "stubs/pathlib2",
+        "stubs/pymssql",
+        "stubs/Routes",
+        "stubs/scribe",
+        "stubs/tornado",
+        // Modules that are incomplete in some way.
+        "stdlib/sqlite3/dbapi2.pyi",
+        "stdlib/tkinter",
+        "stdlib/xml/dom",
+        "stdlib/xml/sax",
+        "stubs/backports",
+        "stubs/backports_abc",
+        "stubs/boto",
+        "stubs/cryptography",
+        "stubs/docutils",
+        "stubs/Flask",
+        "stubs/Jinja2",
+        "stubs/Markdown",
+        "stubs/Pillow",
+        "stubs/paramiko",
+        "stubs/protobuf",
+        "stubs/PyMySQL",
+        "stubs/python-dateutil",
+        "stubs/pyvmomi",
+        "stubs/PyYAML",
+        "stubs/redis",
+        "stubs/requests",
+        "stubs/simplejson",
+        "stubs/waitress",
+        "stubs/Werkzeug"
+    ],
+    "typeCheckingMode": "basic",
+    "strictListInference": true,
+    "strictDictionaryInference": true,
+    "strictParameterNoneValue": true,
+    "reportFunctionMemberAccess": "error",
+    "reportMissingModuleSource": "none",
+    "reportMissingTypeStubs": "error",
+    "reportUnusedImport": "error",
+    "reportUnusedClass": "error",
+    "reportUnusedFunction": "error",
+    "reportUnusedVariable": "error",
+    "reportDuplicateImport": "error",
+    "reportOptionalSubscript": "error",
+    "reportOptionalMemberAccess": "error",
+    "reportOptionalCall": "error",
+    "reportOptionalIterable": "error",
+    "reportOptionalContextManager": "error",
+    "reportOptionalOperand": "error",
+    "reportUntypedFunctionDecorator": "error",
+    "reportUntypedClassDecorator": "error",
+    "reportUntypedBaseClass": "error",
+    "reportUntypedNamedTuple": "error",
+    "reportPrivateUsage": "error",
+    "reportConstantRedefinition": "error",
+    "reportIncompatibleMethodOverride": "error",
+    "reportIncompatibleVariableOverride": "error",
+    "reportInvalidStringEscapeSequence": "error",
+    "reportUnknownParameterType": "error",
+    "reportUnknownArgumentType": "error",
+    "reportUnknownLambdaType": "error",
+    "reportUnknownVariableType": "error",
+    "reportUnknownMemberType": "error",
+    "reportMissingTypeArgument": "error",
+    "reportUndefinedVariable": "error",
+    "reportUnboundVariable": "error",
+    "reportInvalidStubStatement": "error",
+    "reportUnsupportedDunderAll": "error",
+    "reportInvalidTypeVarUse": "error",
+    "reportPropertyTypeMismatch": "error",
+    "reportSelfClsParameterName": "error",
+    // Overlapping overloads cannot be enabled at this time because
+    // of the "factions.Fraction.__pow__" method and "tasks.gather" function.
+    // Mypy's overlapping overload logic misses these issues (see mypy
+    // issue #10143 and #10157).
+    "reportOverlappingOverload": "none"
+}
diff --git a/tests/README.md b/tests/README.md
index 49c6fba51817..a7453ae3aed6 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -47,10 +47,15 @@ This test requires [Node.js](https://nodejs.org) to be installed. It is
 currently not part of the CI,
 but it uses the same pyright version and configuration as the CI.
 ```
-(.venv3)$ python3 tests/pyright_test.py                 # Check all files
-(.venv3)$ python3 tests/pyright_test.py stdlib/sys.pyi  # Check one file
+(.venv3)$ python3 tests/pyright_test.py                                # Check all files
+(.venv3)$ python3 tests/pyright_test.py stdlib/sys.pyi                 # Check one file
+(.venv3)$ python3 tests/pyright_test.py -p pyrightconfig.stricter.json # Check with the stricter config.
 ```
 
+`pyrightconfig.stricter.json` is a stricter configuration that enables additional
+checks that would typically fail on incomplete stubs (such as `Unknown` checks),
+and is run on a subset of stubs (including the standard library).
+
 ## check\_consistent.py
 
 Run using:
diff --git a/tests/pyright_test.py b/tests/pyright_test.py
index 415b381d784e..f811a9668b34 100755
--- a/tests/pyright_test.py
+++ b/tests/pyright_test.py
@@ -5,7 +5,7 @@
 import sys
 from pathlib import Path
 
-_PYRIGHT_VERSION = "1.1.144"  # Must match tests.yml.
+_PYRIGHT_VERSION = "1.1.148"  # Must match tests.yml.
 _WELL_KNOWN_FILE = Path("tests", "pyright_test.py")