diff --git a/testing/python/fixture.py b/testing/python/fixture.py
index f8f5eb54e..fc3eee42b 100644
--- a/testing/python/fixture.py
+++ b/testing/python/fixture.py
@@ -1584,6 +1584,7 @@ class TestFixtureManagerParseFactories(object):
             values = []
         """
         )
+        testdir.syspathinsert(testdir.tmpdir.dirname)
         package = testdir.mkdir("package")
         package.join("__init__.py").write("")
         package.join("conftest.py").write(