diff --git a/lark/parsers/lalr_parser.py b/lark/parsers/lalr_parser.py
index 4a504a4f..35820705 100644
--- a/lark/parsers/lalr_parser.py
+++ b/lark/parsers/lalr_parser.py
@@ -30,7 +30,7 @@ def deserialize(cls, data, memo, callbacks, debug=False):
         inst.parser = _Parser(inst._parse_table, callbacks, debug)
         return inst
 
-    def serialize(self, memo = None) -> Dict[str, Any]:
+    def serialize(self, memo: Any = None) -> Dict[str, Any]:
         return self._parse_table.serialize(memo)
 
     def parse_interactive(self, lexer, start):
diff --git a/lark/utils.py b/lark/utils.py
index 4b7fd8f6..9ad81c8f 100644
--- a/lark/utils.py
+++ b/lark/utils.py
@@ -172,7 +172,7 @@ def get_regexp_width(expr: str) -> Union[Tuple[int, int], List[int]]:
 _ID_START =    'Lu', 'Ll', 'Lt', 'Lm', 'Lo', 'Mn', 'Mc', 'Pc'
 _ID_CONTINUE = _ID_START + ('Nd', 'Nl',)
 
-def _test_unicode_category(s: str, categories: Union[Tuple[str, str, str, str, str, str, str, str], Tuple[str, str, str, str, str, str, str, str, str, str]]) -> bool:
+def _test_unicode_category(s: str, categories: Sequence[str]) -> bool:
     if len(s) != 1:
         return all(_test_unicode_category(char, categories) for char in s)
     return s == '_' or unicodedata.category(s) in categories