diff --git a/swh/lister/opam/tests/test_lister.py b/swh/lister/opam/tests/test_lister.py
index 0079d7a..b39c501 100644
--- a/swh/lister/opam/tests/test_lister.py
+++ b/swh/lister/opam/tests/test_lister.py
@@ -1,170 +1,170 @@
 # Copyright (C) 2021  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import io
 import os
 from tempfile import mkdtemp
 from unittest.mock import MagicMock
 
 import pytest
 
 from swh.lister.opam.lister import OpamLister, opam_init
 
 module_name = "swh.lister.opam.lister"
 
 
 @pytest.fixture
 def mock_opam(mocker):
     """Fixture to bypass the actual opam calls within the test context.
 
     """
     # inhibits the real `subprocess.call` which prepares the required internal opam
     # state
     mock_init = mocker.patch(f"{module_name}.call", return_value=None)
     # replaces the real Popen with a fake one (list origins command)
     mocked_popen = MagicMock()
     mocked_popen.stdout = io.BytesIO(b"bar\nbaz\nfoo\n")
     mock_open = mocker.patch(f"{module_name}.Popen", return_value=mocked_popen)
     return mock_init, mock_open
 
 
 def test_mock_init_repository_init(mock_opam, tmp_path, datadir):
     """Initializing opam root directory with an instance should be ok
 
     """
     mock_init, mock_popen = mock_opam
 
     instance = "fake"
     instance_url = f"file://{datadir}/{instance}"
     opam_root = str(tmp_path / "test-opam")
     assert not os.path.exists(opam_root)
 
     # This will initialize an opam directory with the instance
     opam_init(opam_root, instance, instance_url, {})
 
     assert mock_init.called
 
 
 def test_mock_init_repository_update(mock_opam, tmp_path, datadir):
     """Updating opam root directory with another instance should be ok
 
     """
     mock_init, mock_popen = mock_opam
 
     instance = "fake_opam_repo"
     instance_url = f"file://{datadir}/{instance}"
     opam_root = str(tmp_path / "test-opam")
 
     os.makedirs(opam_root, exist_ok=True)
     with open(os.path.join(opam_root, "opam"), "w") as f:
         f.write("one file to avoid empty folder")
 
     assert os.path.exists(opam_root)
     assert os.listdir(opam_root) == ["opam"]  # not empty
     # This will update the repository opam with another instance
     opam_init(opam_root, instance, instance_url, {})
 
     assert mock_init.called
 
 
 def test_lister_opam_optional_instance(swh_scheduler):
     """Instance name should be optional and default to be built out of the netloc."""
     netloc = "opam.ocaml.org"
     instance_url = f"https://{netloc}"
 
     lister = OpamLister(swh_scheduler, url=instance_url,)
     assert lister.instance == netloc
     assert lister.opam_root == "/tmp/opam/"
 
 
-def test_urls(swh_scheduler, mock_opam):
+def test_urls(swh_scheduler, mock_opam, tmp_path):
     mock_init, mock_popen = mock_opam
     instance_url = "https://opam.ocaml.org"
-    tmp_folder = mkdtemp(prefix="swh_opam_lister")
+    tmp_folder = mkdtemp(dir=tmp_path, prefix="swh_opam_lister")
 
     lister = OpamLister(
         swh_scheduler, url=instance_url, instance="opam", opam_root=tmp_folder,
     )
     assert lister.instance == "opam"
     assert lister.opam_root == tmp_folder
 
     # call the lister and get all listed origins urls
     stats = lister.run()
 
     assert mock_init.called
     assert mock_popen.called
 
     assert stats.pages == 3
     assert stats.origins == 3
 
     scheduler_origins = swh_scheduler.get_listed_origins(lister.lister_obj.id).results
 
     expected_urls = [
         f"opam+{instance_url}/packages/bar/",
         f"opam+{instance_url}/packages/baz/",
         f"opam+{instance_url}/packages/foo/",
     ]
 
     result_urls = [origin.url for origin in scheduler_origins]
 
     assert expected_urls == result_urls
 
 
-def test_opam_binary(datadir, swh_scheduler):
+def test_opam_binary(datadir, swh_scheduler, tmp_path):
     instance_url = f"file://{datadir}/fake_opam_repo"
 
     lister = OpamLister(
         swh_scheduler,
         url=instance_url,
         instance="fake",
-        opam_root=mkdtemp(prefix="swh_opam_lister"),
+        opam_root=mkdtemp(dir=tmp_path, prefix="swh_opam_lister"),
     )
 
     stats = lister.run()
 
     assert stats.pages == 4
     assert stats.origins == 4
 
     scheduler_origins = swh_scheduler.get_listed_origins(lister.lister_obj.id).results
 
     expected_urls = [
         f"opam+{instance_url}/packages/agrid/",
         f"opam+{instance_url}/packages/calculon/",
         f"opam+{instance_url}/packages/directories/",
         f"opam+{instance_url}/packages/ocb/",
     ]
 
     result_urls = [origin.url for origin in scheduler_origins]
 
     assert expected_urls == result_urls
 
 
-def test_opam_multi_instance(datadir, swh_scheduler):
+def test_opam_multi_instance(datadir, swh_scheduler, tmp_path):
     instance_url = f"file://{datadir}/fake_opam_repo"
 
     lister = OpamLister(
         swh_scheduler,
         url=instance_url,
         instance="fake",
-        opam_root=mkdtemp(prefix="swh_opam_lister"),
+        opam_root=mkdtemp(dir=tmp_path, prefix="swh_opam_lister"),
     )
 
     stats = lister.run()
 
     assert stats.pages == 4
     assert stats.origins == 4
 
     scheduler_origins = swh_scheduler.get_listed_origins(lister.lister_obj.id).results
 
     expected_urls = [
         f"opam+{instance_url}/packages/agrid/",
         f"opam+{instance_url}/packages/calculon/",
         f"opam+{instance_url}/packages/directories/",
         f"opam+{instance_url}/packages/ocb/",
     ]
 
     result_urls = [origin.url for origin in scheduler_origins]
 
     assert expected_urls == result_urls