diff --git a/pipenv/patched/piptools/resolver.py b/pipenv/patched/piptools/resolver.py
index 3b5df483..fcc020bf 100755
--- a/pipenv/patched/piptools/resolver.py
+++ b/pipenv/patched/piptools/resolver.py
@@ -295,7 +295,11 @@ class Resolver(object):
         if ireq not in self.dependency_cache:
             log.debug('  {} not in cache, need to check index'.format(format_requirement(ireq)), fg='yellow')
             dependencies = self.repository.get_dependencies(ireq)
-            self.dependency_cache[ireq] = sorted('{0}; {1}'.format(str(ireq.req), str(ireq.markers)) if ireq.markers else str(ireq.req) for ireq in dependencies)
+            import sys
+            if sys.version_info[0] == 2:
+                self.dependency_cache[ireq] = sorted(str(ireq.req) for ireq in dependencies)
+            else:
+                self.dependency_cache[ireq] = sorted('{0}; {1}'.format(str(ireq.req), str(ireq.markers)) if ireq.markers else str(ireq.req) for ireq in dependencies)
 
         # Example: ['Werkzeug>=0.9', 'Jinja2>=2.4']
         dependency_strings = self.dependency_cache[ireq]