diff --git a/stubs/icalendar/METADATA.toml b/stubs/icalendar/METADATA.toml
index 2bec6517e67e..e789388aa886 100644
--- a/stubs/icalendar/METADATA.toml
+++ b/stubs/icalendar/METADATA.toml
@@ -1,4 +1,4 @@
-version = "6.3.*"
+version = "6.3.1"
 upstream_repository = "https://github.com/collective/icalendar"
 requires = ["types-python-dateutil", "types-pytz"]
 
diff --git a/stubs/icalendar/icalendar/parser.pyi b/stubs/icalendar/icalendar/parser.pyi
index 787cafef7bd2..7064af19d664 100644
--- a/stubs/icalendar/icalendar/parser.pyi
+++ b/stubs/icalendar/icalendar/parser.pyi
@@ -58,6 +58,7 @@ def q_join(lst: Iterable[str], sep: str = ",", always_quote: bool = False) -> st
 
 class Parameters(CaselessDict[str]):
     always_quoted: ClassVar[tuple[str, ...]]
+    quote_also: ClassVar[dict[str, str]]
     def params(self) -> dict_keys[str, str]: ...
     def to_ical(self, sorted: bool = True) -> bytes: ...
     @classmethod