diff --git a/setup.py b/setup.py
index 5839d3788..37458a2d5 100644
--- a/setup.py
+++ b/setup.py
@@ -52,7 +52,12 @@ def main():
         install_requires=["py>=1.4.17", "pluggy>=0.3.0,<1.0", "six", "virtualenv>=1.11.2"],
         extras_require={
             "testing": [
-                "pytest >= 3.0.0", "pytest-cov", "pytest-mock", "pytest-timeout", "pytest-xdist"
+                "pytest >= 3.0.0",
+                "pytest-cov",
+                "pytest-mock",
+                "pytest-timeout",
+                "pytest-xdist",
+                "pyannotate",
             ],
             "docs": ["sphinx >= 1.6.3, < 2", "towncrier >= 17.8.0"],
             "lint": ["pre-commit == 1.8.2"],
diff --git a/tox.ini b/tox.ini
index 37effe501..86936d16b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -115,4 +115,4 @@ include_trailing_comma = True
 force_grid_wrap = 0
 line_length = 99
 known_first_party = tox
-known_third_party = pkg_resources,pluggy,py,pytest,setuptools,six
+known_third_party = pkg_resources,pluggy,py,pyannotate_runtime,pytest,setuptools,six
diff --git a/tox/_pytestplugin.py b/tox/_pytestplugin.py
index 5f5133bcd..5c460ee69 100644
--- a/tox/_pytestplugin.py
+++ b/tox/_pytestplugin.py
@@ -39,6 +39,32 @@ def pytest_report_header():
     return "tox comes from: {!r}".format(tox.__file__)
 
 
+def pytest_collection_finish():
+    """Handle the pytest collection finish hook: configure pyannotate.
+    Explicitly delay importing `collect_types` until all tests have
+    been collected.  This gives gevent a chance to monkey patch the
+    world before importing pyannotate.
+    """
+    from pyannotate_runtime import collect_types
+
+    collect_types.init_types_collection()
+
+
+@pytest.fixture(autouse=True)
+def collect_types_fixture():
+    from pyannotate_runtime import collect_types
+
+    collect_types.resume()
+    yield
+    collect_types.pause()
+
+
+def pytest_sessionfinish():
+    from pyannotate_runtime import collect_types
+
+    collect_types.dump_stats("type_info.json")
+
+
 @pytest.fixture
 def work_in_clean_dir(tmpdir):
     with tmpdir.as_cwd():