Hi, Python code should not depend upon the ordering of items in a dict. Unfortunately it seems that a number of tests in the standard library do just that. Changing PyDict_MINSIZE from 8 to either 4 or 16 causes the following tests to fail: test_dis test_email test_inspect test_nntplib test_packaging test_plistlib test_pprint test_symtable test_trace test_sys also fails, but this is a legitimate failure in sys.getsizeof() Changing the collision resolution function from f(n) = 5n + 1 to f(n) = n + 1 results in the same failures, except for test_packaging and test_symtable which pass. Finally, changing the seed in unicode_hash() from (implicit) 0 to an arbitrary value (12345678) causes the above tests to fail plus: test_json test_set test_ttk_textonly test_urllib test_urlparse I think this is a real issue as the unicode_hash() function is likely to change soon due to http://bugs.python.org/issue13703. Should I: 1. Submit one big bug report? 2. Submit a bug report for each "failing" test separately? 3. Ignore it, since the tests only fail when I start messing about? Cheers, Mark.