diff --git a/platypush/plugins/calendar/__init__.py b/platypush/plugins/calendar/__init__.py
index a5e9f4cf..d47e1dac 100644
--- a/platypush/plugins/calendar/__init__.py
+++ b/platypush/plugins/calendar/__init__.py
@@ -27,7 +27,7 @@ class CalendarPlugin(Plugin, CalendarInterface):
         * **dateutil** (``pip install python-dateutil``)
     """
 
-    def __init__(self, calendars=[], *args, **kwargs):
+    def __init__(self, calendars=None, *args, **kwargs):
         """
         :param calendars: List of calendars to be queried. Supported types so far: Google Calendar and iCal URLs.
         :type calendars: list
@@ -49,6 +49,9 @@ class CalendarPlugin(Plugin, CalendarInterface):
         """
 
         super().__init__(*args, **kwargs)
+
+        if calendars is None:
+            calendars = []
         self.calendars = []
 
         for calendar in calendars:
diff --git a/platypush/plugins/calendar/ical.py b/platypush/plugins/calendar/ical.py
index 878324a1..459fb7b7 100644
--- a/platypush/plugins/calendar/ical.py
+++ b/platypush/plugins/calendar/ical.py
@@ -5,15 +5,14 @@
 import datetime
 import dateutil.parser
 import requests
-import pytz
 
-from icalendar import Calendar, Event
+from icalendar import Calendar
 
 from platypush.plugins import Plugin, action
 from platypush.plugins.calendar import CalendarInterface
 
 
-class IcalCalendarPlugin(Plugin, CalendarInterface):
+class CalendarIcalPlugin(Plugin, CalendarInterface):
     """
     iCal calendars plugin. Interact with remote calendars in iCal format.
 
@@ -68,6 +67,8 @@ class IcalCalendarPlugin(Plugin, CalendarInterface):
         :func:`~platypush.plugins.calendar.CalendarPlugin.get_upcoming_events`.
         """
 
+        import pytz
+
         events = []
         try:
             response = requests.get(self.url)