diff --git a/.travis.yml b/.travis.yml
index cf593a5..36f7415 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,7 @@ python:
     - "2.7"
     - "3.3"
     - "3.5"
+    - "3.6"
 install:
     - pip install -r requirements-dev.txt
     - pip install coveralls
diff --git a/README.md b/README.md
index 57158ae..3562743 100644
--- a/README.md
+++ b/README.md
@@ -30,7 +30,7 @@ Read the [Document](http://pyswagger.readthedocs.org/en/latest/), or just go thr
 
 ##Features
 - **NEW** convert Swagger Document from older version to newer one. (ex. convert from 1.2 to 2.0)
-- support Swagger **1.2**, **2.0** on python ~~2.6~~, **2.7**, **3.3**, **3.5**
+- support Swagger **1.2**, **2.0** on python ~~2.6~~, **2.7**, **3.3**, **3.5**, **3.6**
 - support YAML via [Pretty-YAML](https://github.com/mk-fg/pretty-yaml)
 - support $ref to **External Document**, multiple swagger.json will be organized into a group of App. And external document with self-describing resource is also supported (refer to [issue](https://github.com/swagger-api/swagger-spec/issues/219)).
 - type safe, input/output are converted to python types according to [Data Type](https://github.com/wordnik/swagger-spec/blob/master/versions/1.2.md#43-data-types) described in Swagger. You don't need to touch any json schema when using pyswagger. Limitations like **minimum/maximum** or **enum** are also checked. **Model inheritance** also supported.
diff --git a/pyswagger/scanner/v1_2/upgrade.py b/pyswagger/scanner/v1_2/upgrade.py
index 2323797..f65a5f9 100644
--- a/pyswagger/scanner/v1_2/upgrade.py
+++ b/pyswagger/scanner/v1_2/upgrade.py
@@ -177,7 +177,7 @@ def _operation(self, path, obj, app):
         path = obj._parent_.basePath + obj.path
         if path not in self.__swagger.paths:
             self.__swagger.paths[path] = objects.PathItem(NullContext())
- 
+
         method = obj.method.lower()
         self.__swagger.paths[path].update_field(method, o)
 
@@ -247,7 +247,7 @@ def _parameter(self, path, obj, app):
                 o.update_field('uniqueItems', obj.uniqueItems)
                 o.update_field('items', convert_items(obj.items, app))
 
-        path = obj._parent_._parent_.basePath + obj._parent_.path 
+        path = obj._parent_._parent_.basePath + obj._parent_.path
         method = obj._parent_.method.lower()
         op = getattr(self.__swagger.paths[path], method)
         op.parameters.append(o)
@@ -292,7 +292,7 @@ def swagger(self):
         if not self.__swagger:
             return None
 
-        common_path = os.path.commonprefix(self.__swagger.paths.keys())
+        common_path = os.path.commonprefix(list(self.__swagger.paths))
         # remove tailing slash,
         # because all paths in Paths Object would prefixed with slah.
         common_path = common_path[:-1] if common_path[-1] == '/' else common_path