diff --git a/conftest.py b/conftest.py
index 3cccfe1..723e5b4 100644
--- a/conftest.py
+++ b/conftest.py
@@ -1,3 +1,8 @@
+import sys
+
+import pytest
+
+
 pytest_plugins = 'setuptools.tests.fixtures'
 
 
@@ -6,3 +11,40 @@
         "--package_name", action="append", default=[],
         help="list of package_name to pass to test functions",
     )
+    parser.addoption(
+        "--integration", action="store_true", default=False,
+        help="run integration tests (only)"
+    )
+
+
+def pytest_configure(config):
+    config.addinivalue_line("markers", "integration: integration tests")
+    config.addinivalue_line("markers", "uses_network: tests may try to download files")
+
+
+collect_ignore = [
+    'tests/manual_test.py',
+    'setuptools/tests/mod_with_constant.py',
+    'setuptools/_distutils',
+    '_distutils_hack',
+    'setuptools/extern',
+    'pkg_resources/extern',
+    'pkg_resources/tests/data',
+    'setuptools/_vendor',
+    'pkg_resources/_vendor',
+]
+
+
+if sys.version_info < (3, 6):
+    collect_ignore.append('docs/conf.py')  # uses f-strings
+    collect_ignore.append('pavement.py')
+
+
+@pytest.fixture(autouse=True)
+def _skip_integration(request):
+    running_integration_tests = request.config.getoption("--integration")
+    is_integration_test = request.node.get_closest_marker("integration")
+    if running_integration_tests and not is_integration_test:
+        pytest.skip("running integration tests only")
+    if not running_integration_tests and is_integration_test:
+        pytest.skip("skipping integration tests")