diff --git a/stdlib/2/ConfigParser.pyi b/stdlib/2/ConfigParser.pyi
index fa0e55171..d727ded10 100644
--- a/stdlib/2/ConfigParser.pyi
+++ b/stdlib/2/ConfigParser.pyi
@@ -1,4 +1,5 @@
-from typing import Any, IO, Sequence, Tuple, Union, List, Dict, Protocol, Optional
+from typing import Any, IO, Sequence, Tuple, Union, List, Dict, Optional
+from _typeshed import SupportsReadline
 
 DEFAULTSECT: str
 MAX_INTERPOLATION_DEPTH: int
@@ -50,9 +51,6 @@ class MissingSectionHeaderError(ParsingError):
     line: Any
     def __init__(self, filename: str, lineno: Any, line: Any) -> None: ...
 
-class _Readable(Protocol):
-    def readline(self) -> str: ...
-
 class RawConfigParser:
     _dict: Any
     _sections: Dict[Any, Any]
@@ -68,7 +66,7 @@ class RawConfigParser:
     def has_section(self, section: str) -> bool: ...
     def options(self, section: str) -> List[str]: ...
     def read(self, filenames: Union[str, Sequence[str]]) -> List[str]: ...
-    def readfp(self, fp: _Readable, filename: str = ...) -> None: ...
+    def readfp(self, fp: SupportsReadline[str], filename: str = ...) -> None: ...
     def get(self, section: str, option: str) -> str: ...
     def items(self, section: str) -> List[Tuple[Any, Any]]: ...
     def _get(self, section: str, conv: type, option: str) -> Any: ...
diff --git a/stdlib/2/__builtin__.pyi b/stdlib/2/__builtin__.pyi
index 4c531454d..5c203e1ec 100644
--- a/stdlib/2/__builtin__.pyi
+++ b/stdlib/2/__builtin__.pyi
@@ -15,7 +15,7 @@ from io import (
     TextIOWrapper, FileIO, BufferedRandom, BufferedReader, BufferedWriter
 )
 from types import TracebackType, CodeType
-from _typeshed import AnyPath, OpenBinaryMode, OpenTextMode, OpenBinaryModeUpdating, OpenBinaryModeWriting, OpenBinaryModeReading
+from _typeshed import AnyPath, OpenBinaryMode, OpenTextMode, OpenBinaryModeUpdating, OpenBinaryModeWriting, OpenBinaryModeReading, SupportsWrite
 from typing_extensions import Literal
 import sys
 
@@ -1480,17 +1480,13 @@ else:
 
 def ord(__c: Union[Text, bytes]) -> int: ...
 if sys.version_info >= (3,):
-    class _Writer(Protocol):
-        def write(self, __s: str) -> Any: ...
     def print(
-        *values: object, sep: Optional[Text] = ..., end: Optional[Text] = ..., file: Optional[_Writer] = ..., flush: bool = ...
+        *values: object, sep: Optional[Text] = ..., end: Optional[Text] = ..., file: Optional[SupportsWrite[str]] = ..., flush: bool = ...
     ) -> None: ...
 
 else:
-    class _Writer(Protocol):
-        def write(self, __s: Any) -> Any: ...
     # This is only available after from __future__ import print_function.
-    def print(*values: object, sep: Optional[Text] = ..., end: Optional[Text] = ..., file: Optional[_Writer] = ...) -> None: ...
+    def print(*values: object, sep: Optional[Text] = ..., end: Optional[Text] = ..., file: Optional[SupportsWrite[Any]] = ...) -> None: ...
 
 _E = TypeVar("_E", contravariant=True)
 _M = TypeVar("_M", contravariant=True)
diff --git a/stdlib/2/json.pyi b/stdlib/2/json.pyi
index 578e0cd0c..949e3daf7 100644
--- a/stdlib/2/json.pyi
+++ b/stdlib/2/json.pyi
@@ -1,4 +1,5 @@
-from typing import Any, IO, Optional, Tuple, Callable, Dict, List, Union, Text, Protocol, Type
+from typing import Any, IO, Optional, Tuple, Callable, Dict, List, Union, Text, Type
+from _typeshed import SupportsRead
 
 class JSONDecodeError(ValueError):
     def dumps(self, obj: Any) -> str: ...
@@ -43,10 +44,7 @@ def loads(s: Union[Text, bytes],
           object_pairs_hook: Optional[Callable[[List[Tuple[Any, Any]]], Any]] = ...,
           **kwds: Any) -> Any: ...
 
-class _Reader(Protocol):
-    def read(self) -> Union[Text, bytes]: ...
-
-def load(fp: _Reader,
+def load(fp: SupportsRead[Union[Text, bytes]],
          encoding: Optional[str] = ...,
          cls: Optional[Type[JSONDecoder]] = ...,
          object_hook: Optional[Callable[[Dict[Any, Any]], Any]] = ...,
diff --git a/stdlib/2and3/_typeshed/__init__.pyi b/stdlib/2and3/_typeshed/__init__.pyi
index 431d79557..3f64d2e6e 100644
--- a/stdlib/2and3/_typeshed/__init__.pyi
+++ b/stdlib/2and3/_typeshed/__init__.pyi
@@ -13,9 +13,12 @@
 # is not used, types from this module must be quoted.
 
 import sys
-from typing import Protocol, Text, Union, type_check_only
+from typing import Protocol, Text, TypeVar, Union
 from typing_extensions import Literal
 
+_T_co = TypeVar("_T_co", covariant=True)
+_T_contra = TypeVar("_T_contra", contravariant=True)
+
 # StrPath and AnyPath can be used in places where a
 # path can be used instead of a string, starting with Python 3.6.
 if sys.version_info >= (3, 6):
@@ -52,9 +55,15 @@ OpenBinaryModeReading = Literal[
 ]
 OpenBinaryMode = Union[OpenBinaryModeUpdating, OpenBinaryModeReading, OpenBinaryModeWriting]
 
-@type_check_only
 class HasFileno(Protocol):
     def fileno(self) -> int: ...
 
 FileDescriptor = int
 FileDescriptorLike = Union[int, HasFileno]
+
+class SupportsRead(Protocol[_T_co]):
+    def read(self, __length: int = ...) -> _T_co: ...
+class SupportsReadline(Protocol[_T_co]):
+    def readline(self, __length: int = ...) -> _T_co: ...
+class SupportsWrite(Protocol[_T_contra]):
+    def write(self, __s: _T_contra) -> int: ...
diff --git a/stdlib/2and3/builtins.pyi b/stdlib/2and3/builtins.pyi
index 4c531454d..5c203e1ec 100644
--- a/stdlib/2and3/builtins.pyi
+++ b/stdlib/2and3/builtins.pyi
@@ -15,7 +15,7 @@ from io import (
     TextIOWrapper, FileIO, BufferedRandom, BufferedReader, BufferedWriter
 )
 from types import TracebackType, CodeType
-from _typeshed import AnyPath, OpenBinaryMode, OpenTextMode, OpenBinaryModeUpdating, OpenBinaryModeWriting, OpenBinaryModeReading
+from _typeshed import AnyPath, OpenBinaryMode, OpenTextMode, OpenBinaryModeUpdating, OpenBinaryModeWriting, OpenBinaryModeReading, SupportsWrite
 from typing_extensions import Literal
 import sys
 
@@ -1480,17 +1480,13 @@ else:
 
 def ord(__c: Union[Text, bytes]) -> int: ...
 if sys.version_info >= (3,):
-    class _Writer(Protocol):
-        def write(self, __s: str) -> Any: ...
     def print(
-        *values: object, sep: Optional[Text] = ..., end: Optional[Text] = ..., file: Optional[_Writer] = ..., flush: bool = ...
+        *values: object, sep: Optional[Text] = ..., end: Optional[Text] = ..., file: Optional[SupportsWrite[str]] = ..., flush: bool = ...
     ) -> None: ...
 
 else:
-    class _Writer(Protocol):
-        def write(self, __s: Any) -> Any: ...
     # This is only available after from __future__ import print_function.
-    def print(*values: object, sep: Optional[Text] = ..., end: Optional[Text] = ..., file: Optional[_Writer] = ...) -> None: ...
+    def print(*values: object, sep: Optional[Text] = ..., end: Optional[Text] = ..., file: Optional[SupportsWrite[Any]] = ...) -> None: ...
 
 _E = TypeVar("_E", contravariant=True)
 _M = TypeVar("_M", contravariant=True)
diff --git a/stdlib/2and3/ftplib.pyi b/stdlib/2and3/ftplib.pyi
index 0e484a0cb..0c708b369 100644
--- a/stdlib/2and3/ftplib.pyi
+++ b/stdlib/2and3/ftplib.pyi
@@ -9,7 +9,6 @@ from typing import (
     Iterator,
     List,
     Optional,
-    Protocol,
     Text,
     TextIO,
     Tuple,
@@ -20,6 +19,7 @@ from typing import (
 from types import TracebackType
 from socket import socket
 from ssl import SSLContext
+from _typeshed import SupportsRead, SupportsReadline
 
 _T = TypeVar("_T")
 _IntOrStr = Union[int, Text]
@@ -39,12 +39,6 @@ class error_proto(Error): ...
 
 all_errors = Tuple[Type[Exception], ...]
 
-class _Readable(Protocol):
-    def read(self, __length: int) -> bytes: ...
-
-class _ReadLineable(Protocol):
-    def readline(self, _length: int) -> bytes: ...
-
 class FTP:
     debugging: int
 
@@ -118,13 +112,13 @@ class FTP:
     def storbinary(
         self,
         cmd: Text,
-        fp: _Readable,
+        fp: SupportsRead[bytes],
         blocksize: int = ...,
         callback: Optional[Callable[[bytes], Any]] = ...,
         rest: Optional[_IntOrStr] = ...,
     ) -> str: ...
     def retrlines(self, cmd: Text, callback: Optional[Callable[[str], Any]] = ...) -> str: ...
-    def storlines(self, cmd: Text, fp: _ReadLineable, callback: Optional[Callable[[bytes], Any]] = ...) -> str: ...
+    def storlines(self, cmd: Text, fp: SupportsReadline[bytes], callback: Optional[Callable[[bytes], Any]] = ...) -> str: ...
     def acct(self, password: Text) -> str: ...
     def nlst(self, *args: Text) -> List[str]: ...
     # Technically only the last arg can be a Callable but ...
diff --git a/stdlib/2and3/pydoc.pyi b/stdlib/2and3/pydoc.pyi
index 10d5eca5b..c3254dfef 100644
--- a/stdlib/2and3/pydoc.pyi
+++ b/stdlib/2and3/pydoc.pyi
@@ -1,6 +1,7 @@
 import sys
-from typing import Any, AnyStr, Callable, Container, Dict, IO, List, Mapping, MutableMapping, NoReturn, Optional, Protocol, Text, Tuple, Type, Union
+from typing import Any, AnyStr, Callable, Container, Dict, IO, List, Mapping, MutableMapping, NoReturn, Optional, Text, Tuple, Type, Union
 from types import FunctionType, MethodType, ModuleType, TracebackType
+from _typeshed import SupportsWrite
 if sys.version_info >= (3,):
     from reprlib import Repr
 else:
@@ -133,12 +134,10 @@ text: TextDoc
 html: HTMLDoc
 
 class _OldStyleClass: ...
-class _Writable(Protocol):
-    def write(self, __obj: str) -> Any: ...
 
 def resolve(thing: Union[str, object], forceload: bool = ...) -> Optional[Tuple[object, str]]: ...
 def render_doc(thing: Union[str, object], title: str = ..., forceload: bool = ..., renderer: Optional[Doc] = ...) -> str: ...
-def doc(thing: Union[str, object], title: str = ..., forceload: bool = ..., output: Optional[_Writable] = ...) -> None: ...
+def doc(thing: Union[str, object], title: str = ..., forceload: bool = ..., output: Optional[SupportsWrite[str]] = ...) -> None: ...
 def writedoc(thing: Union[str, object], forceload: bool = ...) -> None: ...
 def writedocs(dir: str, pkgpath: str = ..., done: Optional[Any] = ...) -> None: ...
 
diff --git a/stdlib/2and3/pyexpat/__init__.pyi b/stdlib/2and3/pyexpat/__init__.pyi
index 2178302da..edefe954b 100644
--- a/stdlib/2and3/pyexpat/__init__.pyi
+++ b/stdlib/2and3/pyexpat/__init__.pyi
@@ -1,4 +1,5 @@
-from typing import List, Tuple, Optional, Callable, Any, Protocol, Union, Dict, Text
+from typing import List, Tuple, Optional, Callable, Any, Union, Dict, Text
+from _typeshed import SupportsRead
 
 import pyexpat.errors as errors
 import pyexpat.model as model
@@ -15,9 +16,6 @@ class ExpatError(Exception):
 
 error = ExpatError
 
-class _Reader(Protocol):
-    def read(self, length: int) -> bytes: ...
-
 XML_PARAM_ENTITY_PARSING_NEVER: int
 XML_PARAM_ENTITY_PARSING_UNLESS_STANDALONE: int
 XML_PARAM_ENTITY_PARSING_ALWAYS: int
@@ -26,7 +24,7 @@ _Model = Tuple[int, int, Optional[str], tuple]
 
 class XMLParserType(object):
     def Parse(self, __data: Union[Text, bytes], __isfinal: bool = ...) -> int: ...
-    def ParseFile(self, __file: _Reader) -> int: ...
+    def ParseFile(self, __file: SupportsRead[bytes]) -> int: ...
     def SetBase(self, __base: Text) -> None: ...
     def GetBase(self) -> Optional[str]: ...
     def GetInputContext(self) -> Optional[bytes]: ...
diff --git a/stdlib/2and3/shutil.pyi b/stdlib/2and3/shutil.pyi
index 5e8b9183e..780a52e3c 100644
--- a/stdlib/2and3/shutil.pyi
+++ b/stdlib/2and3/shutil.pyi
@@ -3,9 +3,9 @@ import sys
 
 from typing import (
     List, Iterable, Callable, Any, Tuple, Sequence, NamedTuple,
-    AnyStr, Optional, Union, Set, TypeVar, overload, Type, Protocol, Text
+    AnyStr, Optional, Union, Set, TypeVar, overload, Type, Text
 )
-from _typeshed import StrPath
+from _typeshed import StrPath, SupportsRead, SupportsWrite
 
 if sys.version_info >= (3, 6):
     _AnyStr = str
@@ -34,16 +34,7 @@ else:
     class SpecialFileError(EnvironmentError): ...
     class ExecError(EnvironmentError): ...
 
-_S_co = TypeVar("_S_co", covariant=True)
-_S_contra = TypeVar("_S_contra", contravariant=True)
-
-class _Reader(Protocol[_S_co]):
-    def read(self, length: int) -> _S_co: ...
-
-class _Writer(Protocol[_S_contra]):
-    def write(self, data: _S_contra) -> Any: ...
-
-def copyfileobj(fsrc: _Reader[AnyStr], fdst: _Writer[AnyStr],
+def copyfileobj(fsrc: SupportsRead[AnyStr], fdst: SupportsWrite[AnyStr],
                 length: int = ...) -> None: ...
 
 if sys.version_info >= (3,):
diff --git a/stdlib/2and3/traceback.pyi b/stdlib/2and3/traceback.pyi
index e6744007a..8a507e68e 100644
--- a/stdlib/2and3/traceback.pyi
+++ b/stdlib/2and3/traceback.pyi
@@ -1,8 +1,7 @@
-# Stubs for traceback
-
-from typing import Any, Dict, Generator, IO, Iterator, List, Mapping, Optional, Protocol, Tuple, Type, Iterable
+from typing import Any, Dict, Generator, IO, Iterator, List, Mapping, Optional, Tuple, Type, Iterable
 from types import FrameType, TracebackType
 import sys
+from _typeshed import SupportsWrite
 
 _PT = Tuple[str, int, str, Optional[str]]
 
@@ -36,10 +35,8 @@ if sys.version_info >= (3, 5):
     def extract_stack(f: Optional[FrameType] = ...,
                       limit: Optional[int] = ...) -> StackSummary: ...
     def format_list(extracted_list: List[FrameSummary]) -> List[str]: ...
-    class _Writer(Protocol):
-        def write(self, s: str) -> Any: ...
     # undocumented
-    def print_list(extracted_list: List[FrameSummary], file: Optional[_Writer] = ...) -> None: ...
+    def print_list(extracted_list: List[FrameSummary], file: Optional[SupportsWrite[str]] = ...) -> None: ...
 else:
     def extract_tb(tb: Optional[TracebackType], limit: Optional[int] = ...) -> List[_PT]: ...
     def extract_stack(f: Optional[FrameType] = ...,
diff --git a/stdlib/2and3/xml/etree/ElementTree.pyi b/stdlib/2and3/xml/etree/ElementTree.pyi
index 36ac6c90a..1dfaf45d8 100644
--- a/stdlib/2and3/xml/etree/ElementTree.pyi
+++ b/stdlib/2and3/xml/etree/ElementTree.pyi
@@ -11,7 +11,6 @@ from typing import (
     List,
     MutableSequence,
     Optional,
-    Protocol,
     Sequence,
     Text,
     Tuple,
@@ -19,7 +18,7 @@ from typing import (
     Union,
     overload,
 )
-from _typeshed import AnyPath, FileDescriptor
+from _typeshed import AnyPath, FileDescriptor, SupportsWrite
 import sys
 from typing_extensions import Literal
 
@@ -60,9 +59,6 @@ else:
 _file_or_filename = Union[AnyPath, FileDescriptor, IO[Any]]
 
 if sys.version_info >= (3, 8):
-    class _Writeable(Protocol):
-        def write(self, __s: str) -> Any: ...
-
     @overload
     def canonicalize(
         xml_data: Optional[_parser_input_type] = ...,
@@ -81,7 +77,7 @@ if sys.version_info >= (3, 8):
     def canonicalize(
         xml_data: Optional[_parser_input_type] = ...,
         *,
-        out: _Writeable,
+        out: SupportsWrite[str],
         from_file: Optional[_file_or_filename] = ...,
         with_comments: bool = ...,
         strip_text: bool = ...,
diff --git a/stdlib/2and3/xml/sax/saxutils.pyi b/stdlib/2and3/xml/sax/saxutils.pyi
index c6317c95a..d4c9d442b 100644
--- a/stdlib/2and3/xml/sax/saxutils.pyi
+++ b/stdlib/2and3/xml/sax/saxutils.pyi
@@ -1,23 +1,21 @@
 import sys
-from typing import Mapping, Text, Optional, Protocol, Union, TextIO
+from typing import Mapping, Text, Optional, Union, TextIO
 from io import TextIOBase, RawIOBase
 from codecs import StreamWriter, StreamReaderWriter
+from _typeshed import SupportsWrite
 
 from xml.sax import handler
 from xml.sax import xmlreader
 
-class _Writable(Protocol):
-    def write(self, data: str) -> None: ...
-
 def escape(data: Text, entities: Mapping[Text, Text] = ...) -> Text: ...
 def unescape(data: Text, entities: Mapping[Text, Text] = ...) -> Text: ...
 def quoteattr(data: Text, entities: Mapping[Text, Text] = ...) -> Text: ...
 
 class XMLGenerator(handler.ContentHandler):
     if sys.version_info >= (3, 0):
-        def __init__(self, out: Optional[Union[TextIOBase, RawIOBase, StreamWriter, StreamReaderWriter, _Writable]] = ..., encoding: str = ..., short_empty_elements: bool = ...) -> None: ...
+        def __init__(self, out: Optional[Union[TextIOBase, RawIOBase, StreamWriter, StreamReaderWriter, SupportsWrite[str]]] = ..., encoding: str = ..., short_empty_elements: bool = ...) -> None: ...
     else:
-        def __init__(self, out: Optional[Union[TextIOBase, RawIOBase, StreamWriter, StreamReaderWriter, _Writable]] = ..., encoding: Text = ...) -> None: ...
+        def __init__(self, out: Optional[Union[TextIOBase, RawIOBase, StreamWriter, StreamReaderWriter, SupportsWrite[str]]] = ..., encoding: Text = ...) -> None: ...
     def startDocument(self): ...
     def endDocument(self): ...
     def startPrefixMapping(self, prefix, uri): ...
diff --git a/stdlib/3/json/__init__.pyi b/stdlib/3/json/__init__.pyi
index fe8569734..37147330b 100644
--- a/stdlib/3/json/__init__.pyi
+++ b/stdlib/3/json/__init__.pyi
@@ -1,5 +1,6 @@
 import sys
-from typing import Any, IO, Optional, Tuple, Callable, Dict, List, Union, Protocol, Type
+from typing import Any, IO, Optional, Tuple, Callable, Dict, List, Union, Type
+from _typeshed import SupportsRead
 
 from .decoder import JSONDecoder as JSONDecoder
 from .encoder import JSONEncoder as JSONEncoder
@@ -33,7 +34,7 @@ def dump(obj: Any,
          **kwds: Any) -> None: ...
 
 if sys.version_info >= (3, 6):
-    _LoadsString = Union[str, bytes, bytearray]
+    _LoadsString = Union[str, bytes]
 else:
     _LoadsString = str
 def loads(s: _LoadsString,
@@ -46,10 +47,7 @@ def loads(s: _LoadsString,
           object_pairs_hook: Optional[Callable[[List[Tuple[Any, Any]]], Any]] = ...,
           **kwds: Any) -> Any: ...
 
-class _Reader(Protocol):
-    def read(self) -> _LoadsString: ...
-
-def load(fp: _Reader,
+def load(fp: SupportsRead[_LoadsString],
          *,
          cls: Optional[Type[JSONDecoder]] = ...,
          object_hook: Optional[Callable[[Dict[Any, Any]], Any]] = ...,
diff --git a/stdlib/3/xmlrpc/client.pyi b/stdlib/3/xmlrpc/client.pyi
index 931260423..9f48bb879 100644
--- a/stdlib/3/xmlrpc/client.pyi
+++ b/stdlib/3/xmlrpc/client.pyi
@@ -4,19 +4,15 @@ import time
 import gzip
 import http.client
 
-from typing import Any, Callable, Dict, Iterable, List, Mapping, Optional, Protocol, Text, Tuple, Type, TypeVar, Union, overload
+from typing import Any, Callable, Dict, Iterable, List, Mapping, Optional, Protocol, Text, Tuple, Type, Union, overload
 from typing_extensions import Literal
 from types import TracebackType
 from datetime import datetime
+from _typeshed import SupportsRead, SupportsWrite
 
-_T = TypeVar("_T")
-class _HasTimeTuple(Protocol):
+class _SupportsTimeTuple(Protocol):
     def timetuple(self) -> time.struct_time: ...
-class _HasWrite(Protocol):
-    def write(self, __o: str) -> None: ...
-class _HasRead(Protocol):
-    def read(self) -> bytes: ...
-_DateTimeComparable = Union[DateTime, datetime, str, _HasTimeTuple]
+_DateTimeComparable = Union[DateTime, datetime, str, _SupportsTimeTuple]
 _Marshallable = Union[None, bool, int, float, str, bytes, tuple, list, dict, datetime, DateTime, Binary]
 _XMLDate = Union[int, datetime, Tuple[int, ...], time.struct_time]
 _HostType = Union[Tuple[str, Dict[str, str]], str]
@@ -77,7 +73,7 @@ class DateTime:
     def make_comparable(self, other: _DateTimeComparable) -> Tuple[str, str]: ...  # undocumented
     def timetuple(self) -> time.struct_time: ...  # undocumented
     def decode(self, data: Any) -> None: ...
-    def encode(self, out: _HasWrite) -> None: ...
+    def encode(self, out: SupportsWrite[str]) -> None: ...
 
 def _datetime(data: Any) -> DateTime: ...  # undocumented
 def _datetime_type(data: str) -> datetime: ...  # undocumented
@@ -88,7 +84,7 @@ class Binary:
 
     def __init__(self, data: Optional[bytes] = ...) -> None: ...
     def decode(self, data: bytes) -> None: ...
-    def encode(self, out: _HasWrite) -> None: ...
+    def encode(self, out: SupportsWrite[str]) -> None: ...
 
 def _binary(data: bytes) -> Binary: ...  # undocumented
 
@@ -204,7 +200,7 @@ class GzipDecodedResponse(gzip.GzipFile):  # undocumented
 
     io: io.BytesIO
 
-    def __init__(self, response: _HasRead) -> None: ...
+    def __init__(self, response: SupportsRead[bytes]) -> None: ...
     def close(self) -> None: ...
 
 class _Method:  # undocumented
diff --git a/third_party/2and3/toml.pyi b/third_party/2and3/toml.pyi
index d460801b8..aebb4c377 100644
--- a/third_party/2and3/toml.pyi
+++ b/third_party/2and3/toml.pyi
@@ -1,7 +1,8 @@
-from typing import Any, IO, List, Mapping, MutableMapping, Optional, Protocol, Text, Type, Union
+from typing import Any, IO, List, Mapping, MutableMapping, Optional, Text, Type, Union
 from _typeshed import StrPath
 import datetime
 import sys
+from _typeshed import SupportsWrite
 
 if sys.version_info >= (3, 6):
     _PathLike = StrPath
@@ -11,13 +12,10 @@ elif sys.version_info >= (3, 4):
 else:
     _PathLike = StrPath
 
-class _Writable(Protocol):
-    def write(self, obj: str) -> Any: ...
-
 class TomlDecodeError(Exception): ...
 
 def load(f: Union[_PathLike, List[Text], IO[str]], _dict: Type[MutableMapping[str, Any]] = ...) -> MutableMapping[str, Any]: ...
 def loads(s: Text, _dict: Type[MutableMapping[str, Any]] = ...) -> MutableMapping[str, Any]: ...
 
-def dump(o: Mapping[str, Any], f: _Writable) -> str: ...
+def dump(o: Mapping[str, Any], f: SupportsWrite[str]) -> str: ...
 def dumps(o: Mapping[str, Any]) -> str: ...
diff --git a/third_party/2and3/werkzeug/contrib/profiler.pyi b/third_party/2and3/werkzeug/contrib/profiler.pyi
index 61608db97..55941404c 100644
--- a/third_party/2and3/werkzeug/contrib/profiler.pyi
+++ b/third_party/2and3/werkzeug/contrib/profiler.pyi
@@ -1,14 +1,9 @@
-from typing import Any, AnyStr, Generic, Optional, Protocol, Tuple, TypeVar
+from typing import AnyStr, Generic, Tuple
+from _typeshed import SupportsWrite
 
 from ..middleware.profiler import *
 
-_T = TypeVar("_T")
-_T_contra = TypeVar("_T_contra", contravariant=True)
-
-class _Writable(Protocol[_T_contra]):
-    def write(self, __s: _T_contra) -> Any: ...
-
-class MergeStream(Generic[_T]):
-    streams: Tuple[_Writable[_T], ...]
-    def __init__(self, *streams: _Writable[_T]) -> None: ...
-    def write(self, data: _T) -> None: ...
+class MergeStream(Generic[AnyStr]):
+    streams: Tuple[SupportsWrite[AnyStr], ...]
+    def __init__(self, *streams: SupportsWrite[AnyStr]) -> None: ...
+    def write(self, data: AnyStr) -> None: ...
diff --git a/third_party/2and3/werkzeug/datastructures.pyi b/third_party/2and3/werkzeug/datastructures.pyi
index a727df6b7..f62d1dd7c 100644
--- a/third_party/2and3/werkzeug/datastructures.pyi
+++ b/third_party/2and3/werkzeug/datastructures.pyi
@@ -13,7 +13,6 @@ from typing import (
     MutableSet,
     NoReturn,
     Optional,
-    Protocol,
     Text,
     Tuple,
     Type,
@@ -21,6 +20,7 @@ from typing import (
     Union,
     overload,
 )
+from _typeshed import SupportsWrite
 
 _K = TypeVar("_K")
 _V = TypeVar("_V")
@@ -428,9 +428,6 @@ class WWWAuthenticate(UpdateDictMixin, Dict[str, Any]):
     qop: Any
     stale: Any
 
-class _Writer(Protocol):
-    def write(self, data: bytes) -> Any: ...
-
 class FileStorage(object):
     name: Optional[Text]
     stream: IO[bytes]
@@ -453,7 +450,7 @@ class FileStorage(object):
     def mimetype(self) -> str: ...
     @property
     def mimetype_params(self) -> Dict[str, str]: ...
-    def save(self, dst: Union[Text, _Writer], buffer_size: int = ...): ...
+    def save(self, dst: Union[Text, SupportsWrite[bytes]], buffer_size: int = ...): ...
     def close(self) -> None: ...
     def __nonzero__(self) -> bool: ...
     def __bool__(self) -> bool: ...
diff --git a/third_party/2and3/werkzeug/http.pyi b/third_party/2and3/werkzeug/http.pyi
index ff1760a6e..9a4a1e2b9 100644
--- a/third_party/2and3/werkzeug/http.pyi
+++ b/third_party/2and3/werkzeug/http.pyi
@@ -2,7 +2,7 @@ import sys
 from datetime import datetime, timedelta
 from typing import (
     Dict, Text, Union, Tuple, Any, Optional, Mapping, Iterable, Callable, List, Type,
-    TypeVar, Protocol, overload, SupportsInt,
+    TypeVar, overload, SupportsInt,
 )
 from _typeshed.wsgi import WSGIEnvironment
 
diff --git a/third_party/2and3/werkzeug/middleware/lint.pyi b/third_party/2and3/werkzeug/middleware/lint.pyi
index 7531d7752..4fec17aa1 100644
--- a/third_party/2and3/werkzeug/middleware/lint.pyi
+++ b/third_party/2and3/werkzeug/middleware/lint.pyi
@@ -1,5 +1,6 @@
 import sys
 from typing import Any, Iterable, Iterator, List, Mapping, Optional, Protocol, Tuple
+from _typeshed import SupportsWrite
 from _typeshed.wsgi import StartResponse, WSGIApplication, WSGIEnvironment
 
 from ..datastructures import Headers
@@ -9,36 +10,33 @@ class HTTPWarning(Warning): ...
 
 def check_string(context: str, obj: object, stacklevel: int = ...) -> None: ...
 
-class _Readable(Protocol):
+class _SupportsReadEtc(Protocol):
     def read(self, __size: int = ...) -> bytes: ...
     def readline(self, __size: int = ...) -> bytes: ...
     def __iter__(self) -> Iterator[bytes]: ...
     def close(self) -> Any: ...
 
 class InputStream(object):
-    def __init__(self, stream: _Readable) -> None: ...
+    def __init__(self, stream: _SupportsReadEtc) -> None: ...
     def read(self, __size: int = ...) -> bytes: ...
     def readline(self, __size: int = ...) -> bytes: ...
     def __iter__(self) -> Iterator[bytes]: ...
     def close(self) -> None: ...
 
-class _FullyWritable(Protocol):
+class _SupportsWriteEtc(Protocol):
     def write(self, __s: str) -> Any: ...
     def flush(self) -> Any: ...
     def close(self) -> Any: ...
 
 class ErrorStream(object):
-    def __init__(self, stream: _FullyWritable) -> None: ...
+    def __init__(self, stream: _SupportsWriteEtc) -> None: ...
     def write(self, s: str) -> None: ...
     def flush(self) -> None: ...
     def writelines(self, seq: Iterable[str]) -> None: ...
     def close(self) -> None: ...
 
-class _Writable(Protocol):
-    def write(self, __s: str) -> Any: ...
-
 class GuardedWrite(object):
-    def __init__(self, write: _Writable, chunks: List[int]) -> None: ...
+    def __init__(self, write: SupportsWrite[str], chunks: List[int]) -> None: ...
     def __call__(self, s: str) -> None: ...
 
 class GuardedIterator(object):
diff --git a/third_party/2and3/werkzeug/wsgi.pyi b/third_party/2and3/werkzeug/wsgi.pyi
index dbc0c666c..0c6bbedfa 100644
--- a/third_party/2and3/werkzeug/wsgi.pyi
+++ b/third_party/2and3/werkzeug/wsgi.pyi
@@ -1,4 +1,5 @@
-from typing import Any, Optional, Protocol, Iterable, Text
+from typing import Any, Optional, Iterable, Text
+from _typeshed import SupportsRead
 from _typeshed.wsgi import WSGIEnvironment, InputStream
 
 from .middleware.dispatcher import DispatcherMiddleware as DispatcherMiddleware
@@ -26,15 +27,12 @@ class ClosingIterator:
     def __next__(self): ...
     def close(self): ...
 
-class _Readable(Protocol):
-    def read(self, size: int = ...) -> bytes: ...
-
-def wrap_file(environ: WSGIEnvironment, file: _Readable, buffer_size: int = ...) -> Iterable[bytes]: ...
+def wrap_file(environ: WSGIEnvironment, file: SupportsRead[bytes], buffer_size: int = ...) -> Iterable[bytes]: ...
 
 class FileWrapper:
-    file: _Readable
+    file: SupportsRead[bytes]
     buffer_size: int
-    def __init__(self, file: _Readable, buffer_size: int = ...) -> None: ...
+    def __init__(self, file: SupportsRead[bytes], buffer_size: int = ...) -> None: ...
     def close(self) -> None: ...
     def seekable(self) -> bool: ...
     def seek(self, offset: int, whence: int = ...) -> None: ...
diff --git a/third_party/2and3/yaml/cyaml.pyi b/third_party/2and3/yaml/cyaml.pyi
index 0eef81592..689d9ada1 100644
--- a/third_party/2and3/yaml/cyaml.pyi
+++ b/third_party/2and3/yaml/cyaml.pyi
@@ -1,13 +1,12 @@
 from typing import Any, IO, Mapping, Optional, Sequence, Text, Union
-from typing_extensions import Protocol
+from _typeshed import SupportsRead
 
 from yaml.constructor import BaseConstructor, Constructor, SafeConstructor
 from yaml.representer import BaseRepresenter, Representer, SafeRepresenter
 from yaml.resolver import BaseResolver, Resolver
 from yaml.serializer import Serializer
 
-class _Readable(Protocol):
-    def read(self, size: int) -> Union[Text, bytes]: ...
+_Readable = SupportsRead[Union[Text, bytes]]
 
 class CParser:
     def __init__(self, stream: Union[str, bytes, _Readable]) -> None: ...