diff --git a/Pipfile b/Pipfile
index 2b6db107..931d4ad5 100644
--- a/Pipfile
+++ b/Pipfile
@@ -7,5 +7,5 @@ verify_ssl = true
 flake8 = "*"
 
 [packages]
-pytest = "*"
-pytest-xdist = "*"
+pytest = "==6.0.0"
+pytest-xdist = "==1.34.0"
diff --git a/tests/unit_tests/conftest.py b/tests/unit_tests/conftest.py
index f2e1240d..5c69582f 100644
--- a/tests/unit_tests/conftest.py
+++ b/tests/unit_tests/conftest.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2018-2019, XMOS Ltd, All rights reserved
+# Copyright (c) 2018-2020, XMOS Ltd, All rights reserved
 import os.path
 import pytest
 import subprocess
@@ -10,7 +10,7 @@ def pytest_collect_file(parent, path):
     if ((path.ext == ".c" or path.ext == ".xc")
             and (path.basename.startswith("test_")
                  and "_Runner" not in path.basename)):
-        return UnityTestSource(path, parent)
+        return UnityTestSource.from_parent(parent, fspath=path)
 
 
 class UnityTestSource(pytest.File):
@@ -32,13 +32,13 @@ def collect(self):
             test_src_name + '_single_issue.xe')
         test_bin_path_si = os.path.join('bin',
                                         test_bin_name_si)
-        yield UnityTestExecutable(test_bin_path_si, self)
+        yield UnityTestExecutable.from_parent(self, name=test_bin_path_si)
 
         test_bin_name_di = os.path.join(
             test_src_name + '_dual_issue.xe')
         test_bin_path_di = os.path.join('bin',
                                         test_bin_name_di)
-        yield UnityTestExecutable(test_bin_path_di, self)
+        yield UnityTestExecutable.from_parent(self, name=test_bin_path_di)
 
 
 class UnityTestExecutable(pytest.Item):