diff --git a/cli_helpers/tabular_output/output_formatter.py b/cli_helpers/tabular_output/output_formatter.py
index <HASH>..<HASH> 100644
--- a/cli_helpers/tabular_output/output_formatter.py
+++ b/cli_helpers/tabular_output/output_formatter.py
@@ -2,6 +2,7 @@
 """A generic tabular data output formatter interface."""
 
 from __future__ import unicode_literals
+from six import text_type
 from collections import namedtuple
 
 from cli_helpers.compat import (text_type, binary_type, int_types, float_types,
@@ -102,7 +103,7 @@ class TabularOutputFormatter(object):
     @property
     def supported_formats(self):
         """The names of the supported output formats in a :class:`tuple`."""
-        return tuple(self._output_formats.keys())
+        return tuple(map(text_type, self._output_formats.keys()))
 
     @classmethod
     def register_new_formatter(cls, format_name, handler, preprocessors=(),
Return the supported formats as a list of unicode strings.