diff --git a/examples/jsonify_examples.py b/examples/jsonify_examples.py
index 10a2918..db5fc7c 100644
--- a/examples/jsonify_examples.py
+++ b/examples/jsonify_examples.py
@@ -1,5 +1,5 @@
 from flask import Flask, jsonify
-from flask_googlemaps import Map, GoogleMaps, icons, render_template
+from flask_googlemaps import Map, GoogleMaps, icons
 
 app = Flask(__name__, template_folder="templates")
 app.config['GOOGLEMAPS_KEY'] = "AIzaSyAZzeHhs-8JZ7i18MjFuM35dJHq70n3Hx4"
diff --git a/flask_googlemaps/__init__.py b/flask_googlemaps/__init__.py
index f5c15b9..dbc9e33 100644
--- a/flask_googlemaps/__init__.py
+++ b/flask_googlemaps/__init__.py
@@ -260,7 +260,9 @@ def add_rectangle(self,
         if east:
             kwargs['bounds']['east'] = east
 
-        if {'north', 'east', 'south', 'west'} != set(kwargs['bounds'].keys()):
+        if set(
+            ('north', 'east', 'south', 'west')
+        ) != set(kwargs['bounds'].keys()):
             raise AttributeError('rectangle bounds required to rectangles')
 
         kwargs.setdefault('stroke_color', '#FF0000')
@@ -388,7 +390,7 @@ def add_circle(self,
         if radius:
             kwargs['radius'] = radius
 
-        if {'lat', 'lng'} != set(kwargs['center'].keys()):
+        if set(('lat', 'lng')) != set(kwargs['center'].keys()):
             raise AttributeError('circle center coordinates required')
         if 'radius' not in kwargs:
             raise AttributeError('circle radius definition required')
diff --git a/setup.py b/setup.py
index 9cbe943..a9ed971 100644
--- a/setup.py
+++ b/setup.py
@@ -4,7 +4,7 @@
 
 setup(
     name='Flask-GoogleMaps',
-    version='0.2.3',
+    version='0.2.4',
     license='MIT',
     description='Small extension for Flask to make using Google Maps easy',
     long_description=open('README.md').read(),