These are only required with older python versions, but dh_python3 doesn't understand that.

--- a/setup.py
+++ b/setup.py
@@ -92,9 +92,7 @@ setup(
         "parse >= 1.13.1; python_version <= '2.7'",
         # -- MAYBE, related to issue #15:
         # "parse == 1.13.1; python_version <= '2.7'",
-        "enum34; python_version < '3.4'",
         "six >= 1.11",
-        "ordereddict; python_version < '2.7'",
     ],
     extras_require={
         'docs': ["sphinx>=1.2"],
