diff --git a/tests/test_converter.py b/tests/test_converter.py
index 897ec38..60a4adb 100644
--- a/tests/test_converter.py
+++ b/tests/test_converter.py
@@ -1,5 +1,5 @@
 import datetime
-from typing import Tuple
+from typing import Tuple, Any
 
 import pytest
 from pytz import timezone, utc
@@ -57,21 +57,21 @@ def ics_test_event(content: str) -> str:
     return ics_test_cal("BEGIN:VEVENT\r\n{}END:VEVENT\r\n".format(content))
 
 
-def test_empty_calendar():
+def test_empty_calendar() -> None:
     converter = CalendarConverter()
     converter.loads(ics_test_cal(""))
     evnts = converter.events_to_gcal()
     assert evnts == []
 
 
-def test_empty_event():
+def test_empty_event() -> None:
     converter = CalendarConverter()
     converter.loads(ics_test_event(""))
     with pytest.raises(KeyError):
         converter.events_to_gcal()
 
 
-def test_event_no_end():
+def test_event_no_end() -> None:
     converter = CalendarConverter()
     converter.loads(ics_test_event(only_start_date))
     with pytest.raises(ValueError):
@@ -102,11 +102,11 @@ def test_event_no_end():
         "datetime utc duration",
     ],
 )
-def param_events_start_end(request):
+def param_events_start_end(request: Any) -> Any:
     return request.param
 
 
-def test_event_start_end(param_events_start_end: Tuple[str, str, str, str]):
+def test_event_start_end(param_events_start_end: Tuple[str, str, str, str]) -> None:
     (date_type, ics_str, start, end) = param_events_start_end
     converter = CalendarConverter()
     converter.loads(ics_str)
@@ -117,7 +117,7 @@ def test_event_start_end(param_events_start_end: Tuple[str, str, str, str]):
     assert event["end"] == {date_type: end}
 
 
-def test_event_created_updated():
+def test_event_created_updated() -> None:
     converter = CalendarConverter()
     converter.loads(ics_test_event(created_updated))
     events = converter.events_to_gcal()
@@ -142,5 +142,5 @@ def test_event_created_updated():
     ],
     ids=["utc", "with timezone", "date"],
 )
-def test_format_datetime_utc(value: datetime.datetime, expected_str: str):
+def test_format_datetime_utc(value: datetime.datetime, expected_str: str) -> None:
     assert format_datetime_utc(value) == expected_str
diff --git a/tests/test_sync.py b/tests/test_sync.py
index 8680fd1..1e2b953 100644
--- a/tests/test_sync.py
+++ b/tests/test_sync.py
@@ -64,8 +64,8 @@ def gen_events(
     return result
 
 
-def gen_list_to_compare(start: int, stop: int) -> List[Dict[str, str]]:
-    result: List[Dict[str, str]] = []
+def gen_list_to_compare(start: int, stop: int) -> EventList:
+    result: EventList = []
     for i in range(start, stop):
         result.append({"iCalUID": "test{:06d}".format(i)})
     return result
@@ -88,8 +88,8 @@ def get_start_date(event: EventData) -> DateDateTime:
     return result
 
 
-def test_compare():
-    part_len = 20
+def test_compare() -> None:
+    part_len: int = 20
     # [1..2n]
     lst_src = gen_list_to_compare(1, 1 + part_len * 2)
     # [n..3n]
@@ -117,7 +117,7 @@ def test_compare():
 
 
 @pytest.mark.parametrize("no_time", [True, False], ids=["date", "dateTime"])
-def test_filter_events_by_date(no_time: bool):
+def test_filter_events_by_date(no_time: bool) -> None:
     msk = timezone("Europe/Moscow")
     now = utc.localize(datetime.datetime.utcnow())
     msk_now = msk.normalize(now.astimezone(msk))
@@ -150,7 +150,7 @@ def test_filter_events_by_date(no_time: bool):
         assert get_start_date(event) < date_cmp
 
 
-def test_filter_events_to_update():
+def test_filter_events_to_update() -> None:
     msk = timezone("Europe/Moscow")
     now = utc.localize(datetime.datetime.utcnow())
     msk_now = msk.normalize(now.astimezone(msk))
@@ -162,11 +162,11 @@ def test_filter_events_to_update():
     events_old = gen_events(1, 1 + count, msk_now)
     events_new = gen_events(1, 1 + count, date_upd)
 
-    sync1 = CalendarSync(None, None)
+    sync1 = CalendarSync(None, None)  # type: ignore
     sync1.to_update = list(zip(events_new, events_old))
     sync1._filter_events_to_update()
 
-    sync2 = CalendarSync(None, None)
+    sync2 = CalendarSync(None, None)  # type: ignore
     sync2.to_update = list(zip(events_old, events_new))
     sync2._filter_events_to_update()
 
@@ -174,7 +174,7 @@ def test_filter_events_to_update():
     assert sync2.to_update == []
 
 
-def test_filter_events_no_updated():
+def test_filter_events_no_updated() -> None:
     """
     test filtering events that not have 'updated' field
     such events should always pass the filter
@@ -195,7 +195,7 @@ def test_filter_events_no_updated():
             del event["updated"]
         i += 1
 
-    sync = CalendarSync(None, None)
+    sync = CalendarSync(None, None)  # type: ignore
     sync.to_update = list(zip(events_old, events_new))
     sync._filter_events_to_update()
     assert len(sync.to_update) == count // 2