diff --git a/feedgen/entry.py b/feedgen/entry.py
index b1763f1..00e4c94 100644
--- a/feedgen/entry.py
+++ b/feedgen/entry.py
@@ -13,6 +13,7 @@ from datetime import datetime
 import dateutil.parser
 import dateutil.tz
 from feedgen.util import ensure_format
+from six import string_types
 
 
 class FeedEntry(object):
@@ -282,7 +283,7 @@ class FeedEntry(object):
 		:returns: Modification date as datetime.datetime
 		'''
 		if not updated is None:
-			if isinstance(updated, basestring):
+			if isinstance(updated, string_types):
 				updated = dateutil.parser.parse(updated)
 			if not isinstance(updated, datetime):
 				raise ValueError('Invalid datetime format')
@@ -549,7 +550,7 @@ class FeedEntry(object):
 		:returns: Creation date as datetime.datetime
 		'''
 		if not published is None:
-			if isinstance(published, basestring):
+			if isinstance(published, string_types):
 				published = dateutil.parser.parse(published)
 			if not isinstance(published, datetime):
 				raise ValueError('Invalid datetime format')
diff --git a/feedgen/feed.py b/feedgen/feed.py
index 9e3fc4c..bfe1717 100644
--- a/feedgen/feed.py
+++ b/feedgen/feed.py
@@ -17,6 +17,7 @@ from feedgen.entry import FeedEntry
 from feedgen.util import ensure_format
 import feedgen.version
 import sys
+from six import string_types
 
 
 _feedgen_version = feedgen.version.version_str
@@ -431,7 +432,7 @@ class FeedGenerator(object):
 		:returns: Modification date as datetime.datetime
 		'''
 		if not updated is None:
-			if isinstance(updated, basestring):
+			if isinstance(updated, string_types):
 				updated = dateutil.parser.parse(updated)
 			if not isinstance(updated, datetime):
 				raise ValueError('Invalid datetime format')
@@ -670,9 +671,9 @@ class FeedGenerator(object):
 		'''
 		if not generator is None:
 			self.__atom_generator = {'value':generator}
-			if not version in None:
+			if not version is None:
 				self.__atom_generator['version'] = version
-			if not uri in None:
+			if not uri is None:
 				self.__atom_generator['uri'] = uri
 			self.__rss_generator = generator
 		return self.__atom_generator
@@ -846,7 +847,7 @@ class FeedGenerator(object):
 		:returns: Publication date as datetime.datetime
 		'''
 		if not pubDate is None:
-			if isinstance(pubDate, basestring):
+			if isinstance(pubDate, string_types):
 				pubDate = dateutil.parser.parse(pubDate)
 			if not isinstance(pubDate, datetime):
 				raise ValueError('Invalid datetime format')
diff --git a/setup.py b/setup.py
index 059dcb7..87d87ef 100755
--- a/setup.py
+++ b/setup.py
@@ -14,7 +14,7 @@ setup(
 		url = 'http://lkiesow.github.io/python-feedgen',
 		keywords = ['feed','ATOM','RSS','podcast'],
 		license = 'FreeBSD and LGPLv3+',
-		install_requires = ['lxml', 'dateutils'],
+		install_requires = ['lxml', 'dateutils', 'six'],
 		classifiers = [
 			'Development Status :: 4 - Beta',
 			'Development Status :: 5 - Production/Stable',