diff --git a/pyproject.toml b/pyproject.toml
index dddae152..6a6a583a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -16,3 +16,8 @@
 line-length = 80
 # NB: Keep in sync with tox.ini.
 target-version = ['py36', 'py37', 'py38', 'py39', 'py310', 'py311'] #, 'py312'
+
+[tool.pytest.ini_options]
+markers = """
+    skip_cq: Skip tests in the CQ. Should be rarely used!
+"""
diff --git a/run_tests b/run_tests
index bdf383eb..20dad8da 100755
--- a/run_tests
+++ b/run_tests
@@ -36,20 +36,7 @@ def is_ci() -> bool:
 def run_pytest(argv: List[str]) -> int:
     """Returns the exit code from pytest."""
     if is_ci():
-        # TODO(b/266734831): Find out why smoke tests fail.
-        # TODO(b/266734831): Find out why each superproject test takes 8m+.
-        tests_to_skip = (
-            "test_smoke_repo",
-            "test_smoke_git",
-            "test_superproject_get_superproject_invalid_branch",
-            "test_superproject_get_superproject_invalid_url",
-        )
-
-        print("WARNING: Skipping tests:", tests_to_skip)
-        argv = [
-            "-k",
-            " and ".join(f"not {x}" for x in tests_to_skip),
-        ] + argv
+        argv = ["-m", "not skip_cq"] + argv
 
     return pytest.main(argv)
 
diff --git a/tests/test_git_command.py b/tests/test_git_command.py
index ffee023b..16494499 100644
--- a/tests/test_git_command.py
+++ b/tests/test_git_command.py
@@ -21,6 +21,8 @@ import subprocess
 import unittest
 from unittest import mock
 
+import pytest
+
 import git_command
 import wrapper
 
@@ -263,6 +265,7 @@ class UserAgentUnitTest(unittest.TestCase):
         m = re.match(r"^[^ ]+$", os_name)
         self.assertIsNotNone(m)
 
+    @pytest.mark.skip_cq("TODO(b/266734831): Find out why this fails in CQ")
     def test_smoke_repo(self):
         """Make sure repo UA returns something useful."""
         ua = git_command.user_agent.repo
@@ -271,6 +274,7 @@ class UserAgentUnitTest(unittest.TestCase):
         m = re.match(r"^git-repo/[^ ]+ ([^ ]+) git/[^ ]+ Python/[0-9.]+", ua)
         self.assertIsNotNone(m)
 
+    @pytest.mark.skip_cq("TODO(b/266734831): Find out why this fails in CQ")
     def test_smoke_git(self):
         """Make sure git UA returns something useful."""
         ua = git_command.user_agent.git
diff --git a/tests/test_git_superproject.py b/tests/test_git_superproject.py
index 4e66521b..3ceb9320 100644
--- a/tests/test_git_superproject.py
+++ b/tests/test_git_superproject.py
@@ -21,6 +21,7 @@ import tempfile
 import unittest
 from unittest import mock
 
+import pytest
 from test_manifest_xml import sort_attributes
 
 import git_superproject
@@ -145,6 +146,7 @@ class SuperprojectTestCase(unittest.TestCase):
         )
         self.assertIsNone(manifest.superproject)
 
+    @pytest.mark.skip_cq("TODO(b/266734831): Find out why this takes 8m+ in CQ")
     def test_superproject_get_superproject_invalid_url(self):
         """Test with an invalid url."""
         manifest = self.getXmlManifest(
@@ -168,6 +170,7 @@ class SuperprojectTestCase(unittest.TestCase):
         self.assertFalse(sync_result.success)
         self.assertTrue(sync_result.fatal)
 
+    @pytest.mark.skip_cq("TODO(b/266734831): Find out why this takes 8m+ in CQ")
     def test_superproject_get_superproject_invalid_branch(self):
         """Test with an invalid branch."""
         manifest = self.getXmlManifest(