diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 86bb88f31474..d0113a50a8ed 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -79,7 +79,7 @@ jobs:
         with:
           python-version: 3.x
       - run: pip install -r requirements-tests.txt
-      - run: ./tests/mypy_test.py --platform=${{ matrix.platform }} --python-version=${{ matrix.python-version }}
+      - run: python ./tests/mypy_test.py --platform=${{ matrix.platform }} --python-version=${{ matrix.python-version }}
 
   regression-tests:
     name: Run mypy on the test cases
diff --git a/tests/mypy_test.py b/tests/mypy_test.py
old mode 100755
new mode 100644
index 18d38043b267..188250e3fde7
--- a/tests/mypy_test.py
+++ b/tests/mypy_test.py
@@ -25,9 +25,9 @@
     VERSIONS_RE as VERSION_LINE_RE,
     colored,
     get_gitignore_spec,
+    get_recursive_requirements,
     print_error,
     print_success_msg,
-    read_dependencies,
     spec_matches_path,
     strip_comments,
 )
@@ -272,11 +272,19 @@ def add_third_party_files(
         return
     seen_dists.add(distribution)
 
-    dependencies = read_dependencies(distribution)
+    stubs_dir = Path("stubs")
+    dependencies = get_recursive_requirements(distribution)
+
     for dependency in dependencies:
-        add_third_party_files(dependency, files, args, configurations, seen_dists)
+        if dependency in seen_dists:
+            continue
+        seen_dists.add(dependency)
+        files_to_add = sorted((stubs_dir / dependency).rglob("*.pyi"))
+        files.extend(files_to_add)
+        for file in files_to_add:
+            log(args, file, f"included as a dependency of {distribution!r}")
 
-    root = Path("stubs", distribution)
+    root = stubs_dir / distribution
     for name in os.listdir(root):
         if name.startswith("."):
             continue
@@ -348,9 +356,10 @@ def test_third_party_stubs(code: int, args: TestConfig) -> TestResults:
         if spec_matches_path(gitignore_spec, distribution_path):
             continue
 
-        this_code, checked = test_third_party_distribution(distribution, args)
-        code = max(code, this_code)
-        files_checked += checked
+        if distribution_path in args.filter or any(distribution_path in path.parents for path in args.filter):
+            this_code, checked = test_third_party_distribution(distribution, args)
+            code = max(code, this_code)
+            files_checked += checked
 
     return TestResults(code, files_checked)
 
diff --git a/tests/regr_test.py b/tests/regr_test.py
index 2bbf4733d78c..fc9f4b135000 100644
--- a/tests/regr_test.py
+++ b/tests/regr_test.py
@@ -9,7 +9,7 @@
 import subprocess
 import sys
 import tempfile
-from itertools import filterfalse, product
+from itertools import product
 from pathlib import Path
 from typing_extensions import TypeAlias
 
@@ -17,9 +17,9 @@
     PackageInfo,
     colored,
     get_all_testcase_directories,
+    get_recursive_requirements,
     print_error,
     print_success_msg,
-    read_dependencies,
     testcase_dir_from_package_name,
 )
 
@@ -81,13 +81,6 @@ def package_with_test_cases(package_name: str) -> PackageInfo:
 )
 
 
-def get_recursive_requirements(package_name: str, seen: set[str] | None = None) -> list[str]:
-    seen = seen if seen is not None else {package_name}
-    for dependency in filterfalse(seen.__contains__, read_dependencies(package_name)):
-        seen.update(get_recursive_requirements(dependency, seen))
-    return sorted(seen | {package_name})
-
-
 def test_testcase_directory(package: PackageInfo, version: str, platform: str) -> ReturnCode:
     package_name, test_case_directory = package
     is_stdlib = package_name == "stdlib"
diff --git a/tests/utils.py b/tests/utils.py
index ded86fc69441..a7b5fc7906ea 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -1,8 +1,11 @@
 """Utilities that are imported by multiple scripts in the tests directory."""
 
+from __future__ import annotations
+
 import os
 import re
 from functools import cache
+from itertools import filterfalse
 from pathlib import Path
 from typing import NamedTuple
 
@@ -53,6 +56,13 @@ def read_dependencies(distribution: str) -> tuple[str, ...]:
     return tuple(dependencies)
 
 
+def get_recursive_requirements(package_name: str, seen: set[str] | None = None) -> list[str]:
+    seen = seen if seen is not None else {package_name}
+    for dependency in filterfalse(seen.__contains__, read_dependencies(package_name)):
+        seen.update(get_recursive_requirements(dependency, seen))
+    return sorted(seen | {package_name})
+
+
 # ====================================================================
 # Parsing the stdlib/VERSIONS file
 # ====================================================================