diff --git a/swh/loader/core/tests/test_utils.py b/swh/loader/core/tests/test_utils.py
new file mode 100644
--- /dev/null
+++ b/swh/loader/core/tests/test_utils.py
@@ -0,0 +1,95 @@
+# Copyright (C) 2019  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 os
+
+from unittest.mock import patch
+
+from swh.loader.core.utils import clean_dangling_folders
+
+
+def test_clean_dangling_folders_0(tmpdir):
+    """Folder does not exist, do nothing"""
+    r = clean_dangling_folders('/path/does/not/exist', 'unused-pattern')
+    assert r is None
+
+
+@patch('swh.loader.core.utils.psutil.pid_exists')
+def test_clean_dangling_folders_1(mock_pid_exists, tmpdir):
+    """Folder which matches pattern with pid dead are cleaned up
+
+    """
+    # pid is dead
+    mock_pid_exists.return_value = False
+
+    dangling = [
+        tmpdir / 'something',
+        tmpdir / 'swh.loader.svn-4321.noisynoise',
+    ]
+    for d in dangling:
+        os.mkdir(d)
+
+    clean_dangling_folders(tmpdir, 'swh.loader.svn')
+
+    expected_dir = os.listdir(tmpdir)
+
+    mock_pid_exists.assert_called_once_with(4321)
+
+    assert expected_dir == ['something']
+
+
+@patch('swh.loader.core.utils.psutil.pid_exists')
+def test_clean_dangling_folders_2(mock_pid_exists, tmpdir):
+    """Folder which matches pattern with pid alive are skipped
+
+    """
+    # pid is live
+    mock_pid_exists.return_value = True
+
+    dangling = [
+        tmpdir / 'something',
+        tmpdir / 'swh.loader.svn-1234.noisynoise',
+    ]
+    for d in dangling:
+        os.mkdir(d)
+
+    clean_dangling_folders(tmpdir, 'swh.loader.svn')
+
+    expected_dirs = os.listdir(tmpdir)
+    sorted(expected_dirs)
+
+    mock_pid_exists.assert_called_once_with(1234)
+
+    assert expected_dirs == [
+        'swh.loader.svn-1234.noisynoise', 'something',
+    ]
+
+
+@patch('swh.loader.core.utils.psutil.pid_exists')
+@patch('swh.loader.core.utils.shutil.rmtree')
+def test_clean_dangling_folders_3(mock_rmtree, mock_pid_exists, tmpdir):
+    """Error in trying to clean dangling folders are skipped
+
+    """
+    # pid is dead, we can clean up
+    mock_pid_exists.return_value = False
+    # for some reason, this fails to remove the dangling folder
+    mock_rmtree.side_effect = ValueError('Could not remove for reasons')
+
+    path2 = tmpdir / 'swh.loader.git-1468.noisy'
+    dangling_folders = list(map(str, [tmpdir / 'thingy', path2]))
+    sorted(dangling_folders)
+    for d in dangling_folders:
+        os.makedirs(d)
+
+    clean_dangling_folders(tmpdir, 'swh.loader.git')
+
+    expected_dirs = os.listdir(tmpdir)
+    sorted(expected_dirs)
+
+    mock_pid_exists.assert_called_once_with(1468)
+    mock_rmtree.assert_called_once_with(str(path2))
+
+    assert expected_dirs == ['swh.loader.git-1468.noisy', 'thingy']