diff --git a/test/make_test_list.py b/test/make_test_list.py
index d77d59032..971b835cd 100644
--- a/test/make_test_list.py
+++ b/test/make_test_list.py
@@ -5,24 +5,36 @@ Generate a list of test modules in the CPython distribution.
 import os
 from pathlib import Path
 
-tests = []
 
-TEST_DIR = Path("../cpython/build/3.6.4/host/lib/python3.6/test")
+TEST_DIR = (Path(__file__).parent
+            / "cpython/build/3.6.4/host/lib/python3.6/test")
 
-for root, dirs, files in os.walk(
-        "../cpython/build/3.6.4/host/lib/python3.6/test"):
-    root = Path(root).relative_to(TEST_DIR)
-    if root == '.':
-        root = ''
-    else:
-        root = '.'.join(root.split('/')) + '.'
 
-    for filename in files:
-        filename = Path(filename)
-        if str(filename).startswith("test_") and filename.suffix == ".py":
-            tests.append(str(root / filename.stem))
+def collect_tests(base_dir):
+    """Collect CPython unit tests"""
+    # Note: this functionality is somewhat equivalent to pytest test
+    # collection.
+    tests = []
 
-tests.sort()
-with open("python_tests.txt", "w") as fp:
-    for test in tests:
-        fp.write(test + '\n')
+    for root, dirs, files in os.walk(base_dir):
+        root = Path(root).relative_to(base_dir)
+
+        if str(root) == '.':
+            root = ''
+        else:
+            root = '.'.join(str(root).split('/')) + '.'
+
+        for filename in files:
+            filename = Path(filename)
+            if str(filename).startswith("test_") and filename.suffix == ".py":
+                tests.append(root + filename.stem)
+
+    tests.sort()
+    return tests
+
+
+if __name__ == '__main__':
+    tests = collect_tests(TEST_DIR)
+    with open("python_tests.txt", "w") as fp:
+        for test in tests:
+            fp.write(test + '\n')