diff --git a/Lib/test/test_importlib/source/test_file_loader.py b/Lib/test/test_importlib/source/test_file_loader.py
--- a/Lib/test/test_importlib/source/test_file_loader.py
+++ b/Lib/test/test_importlib/source/test_file_loader.py
@@ -185,16 +185,17 @@ class SimpleTest(abc.LoaderTests):
                 self.assertEqual(self.util.cache_from_source(file_path),
                                  mod.__cached__)
         finally:
             os.unlink(file_path)
             pycache = os.path.dirname(self.util.cache_from_source(file_path))
             if os.path.exists(pycache):
                 shutil.rmtree(pycache)
 
+    @source_util.writes_bytecode_files
     def test_timestamp_overflow(self):
         # When a modification timestamp is larger than 2**32, it should be
         # truncated rather than raise an OverflowError.
         with source_util.create_modules('_temp') as mapping:
             source = mapping['_temp']
             compiled = self.util.cache_from_source(source)
             with open(source, 'w') as f:
                 f.write("x = 5")