diff --git a/third_party/2and3/werkzeug/datastructures.pyi b/third_party/2and3/werkzeug/datastructures.pyi
index 4d5f0ec14..a727df6b7 100644
--- a/third_party/2and3/werkzeug/datastructures.pyi
+++ b/third_party/2and3/werkzeug/datastructures.pyi
@@ -1,34 +1,52 @@
 import collections
-from typing import Any, Optional, Mapping, Dict, TypeVar, Callable, Union, overload, Text, Protocol, Iterator, IO
-from collections import Container, Iterable, MutableSet
+from typing import (
+    Any,
+    Callable,
+    Container,
+    Dict,
+    Generic,
+    IO,
+    Iterable,
+    Iterator,
+    List,
+    Mapping,
+    MutableSet,
+    NoReturn,
+    Optional,
+    Protocol,
+    Text,
+    Tuple,
+    Type,
+    TypeVar,
+    Union,
+    overload,
+)
 
 _K = TypeVar("_K")
 _V = TypeVar("_V")
 _R = TypeVar("_R")
 _D = TypeVar("_D")
 
-def is_immutable(self): ...
+def is_immutable(self) -> NoReturn: ...
 def iter_multi_items(mapping): ...
 def native_itermethods(names): ...
 
-class ImmutableListMixin(object):
+class ImmutableListMixin(object, Generic[_V]):
     def __hash__(self) -> int: ...
-    def __reduce_ex__(self, protocol): ...
-    def __delitem__(self, key): ...
-    def __delslice__(self, i, j): ...
-    def __iadd__(self, other): ...
-    __imul__: Any
-    def __setitem__(self, key, value): ...
-    def __setslice__(self, i, j, value): ...
-    def append(self, item): ...
-    remove: Any
-    def extend(self, iterable): ...
-    def insert(self, pos, value): ...
-    def pop(self, index: int = ...): ...
-    def reverse(self): ...
-    def sort(self, cmp: Optional[Any] = ..., key: Optional[Any] = ..., reverse: Optional[Any] = ...): ...
+    def __reduce_ex__(self: _D, protocol) -> Tuple[Type[_D], List[_V]]: ...
+    def __delitem__(self, key: _V) -> NoReturn: ...
+    def __iadd__(self, other: Any) -> NoReturn: ...
+    def __imul__(self, other: Any) -> NoReturn: ...
+    def __setitem__(self, key: str, value: Any) -> NoReturn: ...
+    def append(self, item: Any) -> NoReturn: ...
+    def remove(self, item: Any) -> NoReturn: ...
+    def extend(self, iterable: Any) -> NoReturn: ...
+    def insert(self, pos: int, value: Any) -> NoReturn: ...
+    def pop(self, index: int = ...) -> NoReturn: ...
+    def reverse(self) -> NoReturn: ...
+    def sort(self, cmp: Optional[Any] = ..., key: Optional[Any] = ..., reverse: Optional[Any] = ...) -> NoReturn: ...
 
-class ImmutableList(ImmutableListMixin, list): ...  # type: ignore
+class ImmutableList(ImmutableListMixin[_V], List[_V]): ...  # type: ignore
 
 class ImmutableDictMixin(object):
     @classmethod
@@ -243,27 +261,35 @@ class ImmutableOrderedMultiDict(ImmutableMultiDictMixin, OrderedMultiDict[_K, _V
     def copy(self): ...
     def __copy__(self): ...
 
-class Accept(ImmutableList):
-    provided: Any
-    def __init__(self, values=...): ...
-    def __getitem__(self, key): ...
-    def quality(self, key): ...
-    def __contains__(self, value): ...
-    def index(self, key): ...
-    def find(self, key): ...
-    def values(self): ...
-    def to_header(self): ...
-    def best_match(self, matches, default: Optional[Any] = ...): ...
+class Accept(ImmutableList[Tuple[str, float]]):
+    provided: bool
+    def __init__(self, values: Union[None, Accept, Iterable[Tuple[str, float]]] = ...) -> None: ...
+    @overload
+    def __getitem__(self, key: int) -> Tuple[str, float]: ...
+    @overload
+    def __getitem__(self, s: slice) -> List[Tuple[str, float]]: ...
+    @overload
+    def __getitem__(self, key: str) -> float: ...
+    def quality(self, key: str) -> float: ...
+    def __contains__(self, value: str) -> bool: ...  # type: ignore
+    def index(self, key: Union[str, Tuple[str, float]]) -> int: ...  # type: ignore
+    def find(self, key: Union[str, Tuple[str, float]]) -> int: ...
+    def values(self) -> Iterator[str]: ...
+    def to_header(self) -> str: ...
+    @overload
+    def best_match(self, matches: Iterable[str], default: None = ...) -> Optional[str]: ...
+    @overload
+    def best_match(self, matches: Iterable[str], default: _D) -> Union[str, _D]: ...
     @property
-    def best(self): ...
+    def best(self) -> Optional[str]: ...
 
 class MIMEAccept(Accept):
     @property
-    def accept_html(self): ...
+    def accept_html(self) -> bool: ...
     @property
-    def accept_xhtml(self): ...
+    def accept_xhtml(self) -> bool: ...
     @property
-    def accept_json(self): ...
+    def accept_json(self) -> bool: ...
 
 class LanguageAccept(Accept): ...
 class CharsetAccept(Accept): ...
diff --git a/third_party/2and3/werkzeug/http.pyi b/third_party/2and3/werkzeug/http.pyi
index e3ca6fe00..bdda6d2cd 100644
--- a/third_party/2and3/werkzeug/http.pyi
+++ b/third_party/2and3/werkzeug/http.pyi
@@ -46,7 +46,7 @@ def parse_options_header(value: _Str, multiple: bool = ...) -> Tuple[Any, ...]:
 @overload
 def parse_accept_header(value: Optional[Text]) -> Accept: ...
 @overload
-def parse_accept_header(value: Optional[_Str], cls: Callable[[Optional[_Str]], _T]) -> _T: ...
+def parse_accept_header(value: Optional[_Str], cls: Callable[[Optional[List[Tuple[str, float]]]], _T]) -> _T: ...
 @overload
 def parse_cache_control_header(value: Union[None, bytes, Text],
                                on_update: Optional[Callable[[RequestCacheControl], Any]] = ...) -> RequestCacheControl: ...