diff --git a/khal/khalendar/event.py b/khal/khalendar/event.py
index 58b1499ac..7c3a0bbf2 100644
--- a/khal/khalendar/event.py
+++ b/khal/khalendar/event.py
@@ -69,7 +69,7 @@ def __init__(self,
                  color: Optional[str] = None,
                  start: Optional[dt.datetime] = None,
                  end: Optional[dt.datetime] = None,
-                 ):
+                 ) -> None:
         """
         :param start: start datetime of this event instance
         :param end: end datetime of this event instance
@@ -769,7 +769,7 @@ class LocalizedEvent(DatetimeEvent):
     see parent
     """
 
-    def __init__(self, *args, **kwargs):
+    def __init__(self, *args, **kwargs) -> None:
         super().__init__(*args, **kwargs)
         try:
             starttz = getattr(self._vevents[self.ref]['DTSTART'].dt, 'tzinfo', None)
diff --git a/khal/khalendar/exceptions.py b/khal/khalendar/exceptions.py
index ae903744b..db0c4bc27 100644
--- a/khal/khalendar/exceptions.py
+++ b/khal/khalendar/exceptions.py
@@ -28,7 +28,7 @@ class UnsupportedRruleExceptionError(UnsupportedFeatureError):
 
     """we do not support exceptions that do not delete events yet"""
 
-    def __init__(self, message=''):
+    def __init__(self, message='') -> None:
         x = 'This kind of recurrence exception is currently unsupported'
         if message:
             x += f': {message.strip()}'
diff --git a/khal/khalendar/vdir.py b/khal/khalendar/vdir.py
index 77022c4b2..2b3e688b8 100644
--- a/khal/khalendar/vdir.py
+++ b/khal/khalendar/vdir.py
@@ -29,7 +29,7 @@ class cached_property:
     instances' methods.
     '''
 
-    def __init__(self, fget, doc=None):
+    def __init__(self, fget, doc=None) -> None:
         self.__name__ = fget.__name__
         self.__module__ = fget.__module__
         self.__doc__ = doc or fget.__doc__
@@ -94,7 +94,7 @@ def get_etag_from_file(f) -> str:
 
 
 class VdirError(IOError):
-    def __init__(self, *args, **kwargs):
+    def __init__(self, *args, **kwargs) -> None:
         for key, value in kwargs.items():
             if getattr(self, key, object()) not in [None, '']:  # pragma: no cover
                 raise TypeError(f'Invalid argument: {key}')
@@ -120,7 +120,7 @@ class AlreadyExistingError(VdirError):
 
 
 class Item:
-    def __init__(self, raw: str):
+    def __init__(self, raw: str) -> None:
         assert isinstance(raw, str)
         self.raw = raw
 
@@ -145,7 +145,7 @@ class VdirBase:
     item_class = Item
     default_mode = 0o750
 
-    def __init__(self, path: str, fileext: str, encoding: str='utf-8'):
+    def __init__(self, path: str, fileext: str, encoding: str='utf-8') -> None:
         if not os.path.isdir(path):
             raise CollectionNotFoundError(path)
         self.path = path
@@ -284,7 +284,7 @@ def set_meta(self, key: str, value: str) -> None:
 
 
 class Color:
-    def __init__(self, x: str):
+    def __init__(self, x: str) -> None:
         if not x:
             raise ValueError('Color is false-ish.')
         if not x.startswith('#'):
diff --git a/khal/ui/__init__.py b/khal/ui/__init__.py
index ebe0a7c3c..b3f111826 100644
--- a/khal/ui/__init__.py
+++ b/khal/ui/__init__.py
@@ -102,7 +102,7 @@ def render(self, size, focus=False):
 
 
 class DateHeader(SelectableText):
-    def __init__(self, day: dt.date, dateformat: str, conf):
+    def __init__(self, day: dt.date, dateformat: str, conf) -> None:
         """
         :param day: the date that is represented by this DateHeader instance
         :param dateformat: format to print `day` in
@@ -154,7 +154,7 @@ def keypress(self, _, key: str) -> str:
 
 
 class U_Event(urwid.Text):
-    def __init__(self, event, conf, delete_status, this_date=None, relative=True):
+    def __init__(self, event, conf, delete_status, this_date=None, relative=True) -> None:
         """representation of an event in EventList
 
         :param event: the encapsulated event
@@ -239,7 +239,7 @@ def __init__(
             self, *args, parent, conf,
             delete_status, toggle_delete_instance, toggle_delete_all,
             set_focus_date_callback=None,
-            **kwargs):
+            **kwargs) -> None:
         self._init: bool = True
         self.parent: 'ClassicView' = parent
         self.delete_status = delete_status
@@ -276,7 +276,7 @@ class DListBox(EventListBox):
     """Container for a DayWalker"""
     # XXX unfortunate naming, there is also DateListBox
 
-    def __init__(self, *args, **kwargs):
+    def __init__(self, *args, **kwargs) -> None:
         dynamic_days = kwargs.pop('dynamic_days', True)
         super().__init__(*args, **kwargs)
         self._init = dynamic_days
@@ -352,7 +352,7 @@ class DayWalker(urwid.SimpleFocusListWalker):
     """A list Walker that contains a list of DateListBox objects, each representing
     one day and associated events"""
 
-    def __init__(self, this_date, eventcolumn, conf, collection, delete_status):
+    def __init__(self, this_date, eventcolumn, conf, collection, delete_status) -> None:
         self.eventcolumn = eventcolumn
         self._conf = conf
         self.delete_status = delete_status
@@ -577,11 +577,11 @@ class DateListBox(urwid.ListBox):
 
     selected_date = None
 
-    def __init__(self, content, date):
+    def __init__(self, content, date) -> None:
         self.date = date
         super().__init__(content)
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return f'<DateListBox {self.date}>'
 
     __str__ = __repr__
@@ -633,7 +633,7 @@ class EventColumn(urwid.WidgetWrap):
     Handles modifying events, showing events' details and editing them
     """
 
-    def __init__(self, elistbox, pane):
+    def __init__(self, elistbox, pane) -> None:
         self.pane = pane
         self._conf = pane._conf
         self.divider = urwid.Divider('─')
@@ -955,7 +955,7 @@ def render(self, a, focus):
 class EventDisplay(urwid.WidgetWrap):
     """A widget showing one Event()'s details """
 
-    def __init__(self, conf, event, collection=None):
+    def __init__(self, conf, event, collection=None) -> None:
         self._conf = conf
         self.collection = collection
         self.event = event
@@ -1017,7 +1017,7 @@ def __init__(self, conf, event, collection=None):
 class SearchDialog(urwid.WidgetWrap):
     """A Search Dialog Widget"""
 
-    def __init__(self, search_func, abort_func):
+    def __init__(self, search_func, abort_func) -> None:
 
         class Search(Edit):
 
@@ -1052,7 +1052,7 @@ class ClassicView(Pane):
     on the right
     """
 
-    def __init__(self, collection, conf=None, title: str='', description: str=''):
+    def __init__(self, collection, conf=None, title: str='', description: str='') -> None:
         self.init = True
         # Will be set when opening the view inside a Window
         self.window = None
diff --git a/khal/ui/base.py b/khal/ui/base.py
index ad5659143..032b0eade 100644
--- a/khal/ui/base.py
+++ b/khal/ui/base.py
@@ -41,7 +41,7 @@ class Pane(urwid.WidgetWrap):
 
     """An abstract Pane to be used in a Window object."""
 
-    def __init__(self, widget, title=None, description=None):
+    def __init__(self, widget, title=None, description=None) -> None:
         self.widget = widget
         urwid.WidgetWrap.__init__(self, widget)
         self._title = title or ''
diff --git a/khal/ui/calendarwidget.py b/khal/ui/calendarwidget.py
index 87c7435ad..34b2d9844 100644
--- a/khal/ui/calendarwidget.py
+++ b/khal/ui/calendarwidget.py
@@ -57,7 +57,7 @@ class DatePart(urwid.Text):
 
     """used in the Date widget (single digit)"""
 
-    def __init__(self, digit: str):
+    def __init__(self, digit: str) -> None:
         super().__init__(digit)
 
     @classmethod
@@ -82,7 +82,7 @@ class Date(urwid.WidgetWrap):
 
     """used in the main calendar for dates (a number)"""
 
-    def __init__(self, date: dt.date, get_styles: GetStylesSignature):
+    def __init__(self, date: dt.date, get_styles: GetStylesSignature) -> None:
         dstr = str(date.day).rjust(2)
         self.halves = [urwid.AttrMap(DatePart(dstr[:1]), None, None),
                        urwid.AttrMap(DatePart(dstr[1:]), None, None)]
@@ -142,7 +142,7 @@ def __init__(self,
                  on_press: OnPressType,
                  keybindings: Dict[str, List[str]],
                  get_styles: GetStylesSignature,
-                 **kwargs):
+                 **kwargs) -> None:
         self.on_date_change = on_date_change
         self.on_press = on_press
         self.keybindings = keybindings
@@ -236,7 +236,7 @@ class CListBox(urwid.ListBox):
     it should contain a `CalendarWalker` instance which it autoextends on
     rendering, if needed """
 
-    def __init__(self, walker: 'CalendarWalker'):
+    def __init__(self, walker: 'CalendarWalker') -> None:
         self._init: bool = True
         self.keybindings = walker.keybindings
         self.on_press = walker.on_press
@@ -595,7 +595,7 @@ def __init__(self,
                  monthdisplay: Literal['firstday', 'firstfullweek']='firstday',
                  get_styles: Optional[GetStylesSignature]=None,
                  initial: Optional[dt.date]=None,
-                 ):
+                 ) -> None:
         """A calendar widget that can be used in urwid applications
 
         :param on_date_change: a function that is called every time the selected
diff --git a/khal/ui/editor.py b/khal/ui/editor.py
index 1063a4dba..fa6498f13 100644
--- a/khal/ui/editor.py
+++ b/khal/ui/editor.py
@@ -46,7 +46,7 @@
 
 class StartEnd:
 
-    def __init__(self, startdate, starttime, enddate, endtime):
+    def __init__(self, startdate, starttime, enddate, endtime) -> None:
         """collecting some common properties"""
         self.startdate = startdate
         self.starttime = starttime
@@ -56,7 +56,7 @@ def __init__(self, startdate, starttime, enddate, endtime):
 
 class CalendarPopUp(urwid.PopUpLauncher):
     def __init__(self, widget, on_date_change, weeknumbers=False,
-                 firstweekday=0, monthdisplay='firstday', keybindings=None):
+                 firstweekday=0, monthdisplay='firstday', keybindings=None) -> None:
         self._on_date_change = on_date_change
         self._weeknumbers = weeknumbers
         self._monthdisplay = monthdisplay
@@ -112,7 +112,7 @@ def __init__(
         firstweekday: int=0,
         monthdisplay: Literal['firstday', 'firstfullweek']='firstday',
         keybindings: Optional[Dict[str, List[str]]] = None,
-    ):
+    ) -> None:
         datewidth = len(startdt.strftime(dateformat)) + 1
         self._dateformat = dateformat
         if startdt is None:
@@ -161,7 +161,7 @@ def __init__(self, start, end, conf,
                  on_start_date_change=lambda x: None,
                  on_end_date_change=lambda x: None,
 
-                 ):
+                 ) -> None:
         """
         :type start: datetime.datetime
         :type end: datetime.datetime
@@ -336,7 +336,7 @@ def validate(self):
 class EventEditor(urwid.WidgetWrap):
     """Widget that allows Editing one `Event()`"""
 
-    def __init__(self, pane, event, save_callback=None, always_save=False):
+    def __init__(self, pane, event, save_callback=None, always_save=False) -> None:
         """
         :type event: khal.event.Event
         :param save_callback: call when saving event with new start and end
@@ -572,7 +572,7 @@ def keypress(self, size, key):
 
 
 class WeekDaySelector(urwid.WidgetWrap):
-    def __init__(self, startdt, selected_days):
+    def __init__(self, startdt, selected_days) -> None:
 
         self._weekday_boxes = {day: urwid.CheckBox(day, state=False) for day in WEEKDAYS}
         weekday = startdt.weekday()
@@ -590,7 +590,7 @@ def days(self):
 
 class RecurrenceEditor(urwid.WidgetWrap):
 
-    def __init__(self, rrule, conf, startdt):
+    def __init__(self, rrule, conf, startdt) -> None:
         self._conf = conf
         self._startdt = startdt
         self._rrule = rrule
@@ -797,7 +797,7 @@ def active(self, val):
 
 
 class ExportDialog(urwid.WidgetWrap):
-    def __init__(self, this_func, abort_func, event):
+    def __init__(self, this_func, abort_func, event) -> None:
         lines = []
         lines.append(urwid.Text('Export event as ICS file'))
         lines.append(urwid.Text(''))
diff --git a/khal/ui/widgets.py b/khal/ui/widgets.py
index 050269863..7be6413b9 100644
--- a/khal/ui/widgets.py
+++ b/khal/ui/widgets.py
@@ -124,7 +124,7 @@ def _goto_end_of_line(self):
 
 class DateTimeWidget(ExtendedEdit):
 
-    def __init__(self, dateformat: str, on_date_change=lambda x: None, **kwargs):
+    def __init__(self, dateformat: str, on_date_change=lambda x: None, **kwargs) -> None:
         self.dateformat = dateformat
         self.on_date_change = on_date_change
         super().__init__(wrap='any', **kwargs)
@@ -202,7 +202,7 @@ def _get_current_value(self):
 class Choice(urwid.PopUpLauncher):
     def __init__(
             self, choices, active, decorate_func=None, overlay_width=32, callback=lambda: None,
-    ):
+    ) -> None:
         self.choices = choices
         self._callback = callback
         self._decorate = decorate_func or (lambda x: x)
@@ -243,7 +243,7 @@ class ChoiceList(urwid.WidgetWrap):
     """A pile of Button() widgets, intended to be used with Choice()"""
     signals = ['close']
 
-    def __init__(self, parent, callback=lambda: None):
+    def __init__(self, parent, callback=lambda: None) -> None:
         self.parent = parent
         self._callback = callback
         buttons = []
@@ -275,7 +275,7 @@ class SupportsNext:
     _select_last_selectable
     """
 
-    def __init__(self, *args, **kwargs):
+    def __init__(self, *args, **kwargs) -> None:
         self.outermost = kwargs.get('outermost', False)
         if 'outermost' in kwargs:
             kwargs.pop('outermost')
@@ -398,7 +398,7 @@ def keypress(self, size, key):
 
 
 class ValidatedEdit(urwid.WidgetWrap):
-    def __init__(self, *args, EditWidget=ExtendedEdit, validate=False, **kwargs):
+    def __init__(self, *args, EditWidget=ExtendedEdit, validate=False, **kwargs) -> None:
         assert validate
         self._validate_func = validate
         self._original_widget = urwid.AttrMap(EditWidget(*args, **kwargs), 'edit', 'edit focused')
@@ -446,7 +446,7 @@ def keypress(self, size, key):
 
 
 class PositiveIntEdit(ValidatedEdit):
-    def __init__(self, *args, EditWidget=ExtendedEdit, validate=False, **kwargs):
+    def __init__(self, *args, EditWidget=ExtendedEdit, validate=False, **kwargs) -> None:
         """Variant of Validated Edit that only accepts positive integers."""
         super().__init__(*args, validate=self._unsigned_int, **kwargs)
 
@@ -478,7 +478,7 @@ def _convert_timedelta(dt):
         seconds = int(seconds % 60)
         return days, hours, minutes, seconds
 
-    def __init__(self, dt):
+    def __init__(self, dt) -> None:
         days, hours, minutes, seconds = self._convert_timedelta(dt)
 
         self.days_edit = ValidatedEdit(
@@ -515,7 +515,7 @@ class AlarmsEditor(urwid.WidgetWrap):
 
     class AlarmEditor(urwid.WidgetWrap):
 
-        def __init__(self, alarm, delete_handler):
+        def __init__(self, alarm, delete_handler) -> None:
             duration, description = alarm
             if duration.total_seconds() > 0:
                 direction = 'after'
@@ -546,7 +546,7 @@ def get_alarm(self):
                 prefix = 1
             return (prefix * self.duration.get_timedelta(), self.description.get_edit_text())
 
-    def __init__(self, event):
+    def __init__(self, event) -> None:
         self.event = event
 
         self.pile = NPile(
@@ -581,7 +581,7 @@ def changed(self):
 
 
 class FocusLineBoxWidth(urwid.WidgetDecoration, urwid.WidgetWrap):
-    def __init__(self, widget):
+    def __init__(self, widget) -> None:
         hline = urwid.Divider('─')
         hline_focus = urwid.Divider('━')
         self._vline = urwid.SolidFill('│')
@@ -634,7 +634,7 @@ def render(self, size, focus):
 
 
 class FocusLineBoxColor(urwid.WidgetDecoration, urwid.WidgetWrap):
-    def __init__(self, widget):
+    def __init__(self, widget) -> None:
         hline = urwid.Divider('─')
         self._vline = urwid.AttrMap(urwid.SolidFill('│'), 'frame')
         self._topline = urwid.AttrMap(
@@ -677,7 +677,7 @@ def render(self, size, focus):
 
 
 class FocusLineBoxTop(urwid.WidgetDecoration, urwid.WidgetWrap):
-    def __init__(self, widget):
+    def __init__(self, widget) -> None:
         topline = urwid.AttrMap(urwid.Divider('━'), 'frame')
         self._all = urwid.Pile([('flow', topline), widget], focus_item=1)
         urwid.WidgetWrap.__init__(self, self._all)
diff --git a/khal/utils.py b/khal/utils.py
index ef13edd58..cac1226ef 100644
--- a/khal/utils.py
+++ b/khal/utils.py
@@ -31,6 +31,7 @@
 from typing import Iterator, List, Optional, Tuple
 
 import pytz
+import urwid
 
 
 def generate_random_uid() -> str:
@@ -177,5 +178,5 @@ def relative_timedelta_str(day: dt.date) -> str:
     return f'{approx}{count} {unit} {direction}'
 
 
-def get_wrapped_text(widget):
+def get_wrapped_text(widget: urwid.AttrMap) -> str:
     return widget.original_widget.get_edit_text()
diff --git a/tests/cli_test.py b/tests/cli_test.py
index 3b0fb50b4..f2b827103 100644
--- a/tests/cli_test.py
+++ b/tests/cli_test.py
@@ -14,7 +14,7 @@
 
 class CustomCliRunner(CliRunner):
     def __init__(self, config_file, db=None, calendars=None,
-                 xdg_data_home=None, xdg_config_home=None, tmpdir=None, **kwargs):
+                 xdg_data_home=None, xdg_config_home=None, tmpdir=None, **kwargs) -> None:
         self.config_file = config_file
         self.db = db
         self.calendars = calendars
diff --git a/tests/utils.py b/tests/utils.py
index cfcf636a9..14b4e317a 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -136,6 +136,6 @@ def _replace_uid(event):
 
 
 class DumbItem:
-    def __init__(self, raw, uid):
+    def __init__(self, raw, uid) -> None:
         self.raw = raw
         self.uid = uid