diff --git a/kloppy/domain/models/time.py b/kloppy/domain/models/time.py
index 565f4b56..d20eab09 100644
--- a/kloppy/domain/models/time.py
+++ b/kloppy/domain/models/time.py
@@ -241,13 +241,20 @@ def ranges(self) -> List[Tuple[Time, Time, T]]:
         return ranges_
 
     def last(self, include_time: bool = False, default=SENTINEL):
+        def __get_last_non_none_key(items):
+            for key, value in reversed(items.items()):
+                if value is not None:
+                    return key
+            return None
+
         if not len(self.items):
             if default == SENTINEL:
                 raise KeyError
             else:
                 return default
 
-        time = self.items.keys()[-1]
+        time = __get_last_non_none_key(self.items)
+
         if include_time:
             return time, self.items[time]
         else:
diff --git a/kloppy/infra/serializers/event/statsperform/parsers/f24_xml.py b/kloppy/infra/serializers/event/statsperform/parsers/f24_xml.py
index f32dbd95..58e65980 100644
--- a/kloppy/infra/serializers/event/statsperform/parsers/f24_xml.py
+++ b/kloppy/infra/serializers/event/statsperform/parsers/f24_xml.py
@@ -57,7 +57,7 @@ def extract_events(self) -> List[OptaEvent]:
     def extract_date(self) -> Optional[str]:
         """Return the date of the game."""
         game_elm = self.root.find("Game")
-        if game_elm and "game_date" in game_elm.attrib:
+        if game_elm is not None and "game_date" in game_elm.attrib:
             return parse(game_elm.attrib["game_date"]).astimezone(timezone.utc)
         else:
             return None
@@ -65,15 +65,15 @@ def extract_date(self) -> Optional[str]:
     def extract_game_week(self) -> Optional[str]:
         """Return the game_week of the game."""
         game_elm = self.root.find("Game")
-        if game_elm and "matchday" in game_elm.attrib:
+        if game_elm is not None and "matchday" in game_elm.attrib:
             return game_elm.attrib["matchday"]
         else:
             return None
 
     def extract_game_id(self) -> Optional[str]:
         """Return the game_id of the game."""
-        game_elm = self.root.find("Game")
-        if game_elm and "id" in game_elm.attrib:
+        game_elm: Optional[Element] = self.root.find("Game")
+        if game_elm is not None and "id" in game_elm.attrib:
             return game_elm.attrib["id"]
         else:
             return None