diff --git a/testing/python/collect.py b/testing/python/collect.py
index bc7462674..df6070b8d 100644
--- a/testing/python/collect.py
+++ b/testing/python/collect.py
@@ -34,8 +34,6 @@ class TestModule(object):
         )
 
     def test_import_prepend_append(self, testdir, monkeypatch):
-        syspath = list(sys.path)
-        monkeypatch.setattr(sys, "path", syspath)
         root1 = testdir.mkdir("root1")
         root2 = testdir.mkdir("root2")
         root1.ensure("x456.py")
diff --git a/testing/test_assertrewrite.py b/testing/test_assertrewrite.py
index bdfbf823c..a92ffcf75 100644
--- a/testing/test_assertrewrite.py
+++ b/testing/test_assertrewrite.py
@@ -1335,7 +1335,7 @@ class TestEarlyRewriteBailout(object):
         # Setup conditions for py's fspath trying to import pathlib on py34
         # always (previously triggered via xdist only).
         # Ref: https://github.com/pytest-dev/py/pull/207
-        monkeypatch.setattr(sys, "path", [""] + sys.path)
+        monkeypatch.syspath_prepend("")
         monkeypatch.delitem(sys.modules, "pathlib", raising=False)
 
         testdir.makepyfile(