diff --git a/stdlib/_json.pyi b/stdlib/_json.pyi
index 7395288afdbc..36b0ed679502 100644
--- a/stdlib/_json.pyi
+++ b/stdlib/_json.pyi
@@ -1,5 +1,7 @@
 from typing import Any, Callable
+from typing_extensions import final
 
+@final
 class make_encoder:
     sort_keys: Any
     skipkeys: Any
@@ -23,6 +25,7 @@ class make_encoder:
     ) -> None: ...
     def __call__(self, obj: object, _current_indent_level: int) -> Any: ...
 
+@final
 class make_scanner:
     object_hook: Any
     object_pairs_hook: Any
diff --git a/stdlib/_tkinter.pyi b/stdlib/_tkinter.pyi
index 7c0ccec1d7de..382b7f52f382 100644
--- a/stdlib/_tkinter.pyi
+++ b/stdlib/_tkinter.pyi
@@ -101,6 +101,7 @@ WRITABLE: Literal[4]
 TCL_VERSION: str
 TK_VERSION: str
 
+@final
 class TkttType:
     def deletetimerhandler(self): ...
 
diff --git a/stdlib/hashlib.pyi b/stdlib/hashlib.pyi
index fad3c5aad457..3b8fbeb0bf3e 100644
--- a/stdlib/hashlib.pyi
+++ b/stdlib/hashlib.pyi
@@ -1,6 +1,7 @@
 import sys
 from _typeshed import ReadableBuffer, Self
 from typing import AbstractSet
+from typing_extensions import final
 
 class _Hash:
     @property
@@ -76,7 +77,7 @@ def scrypt(
     maxmem: int = ...,
     dklen: int = ...,
 ) -> bytes: ...
-
+@final
 class _BlakeHash(_Hash):
     MAX_DIGEST_SIZE: int
     MAX_KEY_SIZE: int
diff --git a/stdlib/sqlite3/dbapi2.pyi b/stdlib/sqlite3/dbapi2.pyi
index 820b40baa47b..7e0d2e6a0d33 100644
--- a/stdlib/sqlite3/dbapi2.pyi
+++ b/stdlib/sqlite3/dbapi2.pyi
@@ -2,6 +2,7 @@ import sys
 from _typeshed import Self, StrOrBytesPath
 from datetime import date, datetime, time
 from typing import Any, Callable, Generator, Iterable, Iterator, Protocol, TypeVar
+from typing_extensions import final
 
 _T = TypeVar("_T")
 
@@ -223,6 +224,7 @@ class OperationalError(DatabaseError): ...
 
 OptimizedUnicode = str
 
+@final
 class PrepareProtocol:
     def __init__(self, *args: Any, **kwargs: Any) -> None: ...
 
diff --git a/stdlib/ssl.pyi b/stdlib/ssl.pyi
index 28f616eceabf..fb9acb011e4c 100644
--- a/stdlib/ssl.pyi
+++ b/stdlib/ssl.pyi
@@ -3,7 +3,7 @@ import socket
 import sys
 from _typeshed import ReadableBuffer, Self, StrOrBytesPath, WriteableBuffer
 from typing import Any, Callable, ClassVar, Iterable, NamedTuple, Optional, Union, overload
-from typing_extensions import Literal, TypedDict
+from typing_extensions import Literal, TypedDict, final
 
 _PCTRTT = tuple[tuple[str, str], ...]
 _PCTRTTT = tuple[_PCTRTT, ...]
@@ -471,6 +471,7 @@ class SSLObject:
     if sys.version_info >= (3, 8):
         def verify_client_post_handshake(self) -> None: ...
 
+@final
 class MemoryBIO:
     pending: int
     eof: bool
@@ -478,6 +479,7 @@ class MemoryBIO:
     def write(self, __buf: bytes) -> int: ...
     def write_eof(self) -> None: ...
 
+@final
 class SSLSession:
     id: bytes
     time: int
diff --git a/stdlib/unicodedata.pyi b/stdlib/unicodedata.pyi
index ead25ba4062c..dca88caa7c1f 100644
--- a/stdlib/unicodedata.pyi
+++ b/stdlib/unicodedata.pyi
@@ -1,5 +1,6 @@
 import sys
 from typing import Any, TypeVar
+from typing_extensions import final
 
 ucd_3_2_0: UCD
 ucnhash_CAPI: Any
@@ -23,7 +24,7 @@ def mirrored(__chr: str) -> int: ...
 def name(__chr: str, __default: _T = ...) -> str | _T: ...
 def normalize(__form: str, __unistr: str) -> str: ...
 def numeric(__chr: str, __default: _T = ...) -> float | _T: ...
-
+@final
 class UCD:
     # The methods below are constructed from the same array in C
     # (unicodedata_functions) and hence identical to the methods above.