diff --git a/pyproject.toml b/pyproject.toml
index 0cf57ab0b..e9087204d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -74,6 +74,7 @@ dev = [
     "pexpect",
     "pre-commit",
     "pytest",
+    "pytest-benchmark",
 ]
 full = [
     "ipywidgets",
diff --git a/test/conftest.py b/test/conftest.py
new file mode 100644
index 000000000..4c57d3368
--- /dev/null
+++ b/test/conftest.py
@@ -0,0 +1,11 @@
+# Code that gets run before pytest runs..
+import gc
+
+
+def pytest_sessionfinish(session, exitstatus):
+    """Executes after all tests have completed.
+
+    Freeze objects right before pytest exits. This prevents PyGC_Collect from
+    walking Generation 2 objects during _Py_Finalize.
+    """
+    gc.freeze()