diff --git a/stdlib/_zstd.pyi b/stdlib/_zstd.pyi
index 2730232528fc..cf75ad89a35f 100644
--- a/stdlib/_zstd.pyi
+++ b/stdlib/_zstd.pyi
@@ -45,9 +45,9 @@ class ZstdCompressor:
     CONTINUE: Final = 0
     FLUSH_BLOCK: Final = 1
     FLUSH_FRAME: Final = 2
-    def __init__(
+    def __new__(
         self, level: int | None = None, options: Mapping[int, int] | None = None, zstd_dict: ZstdDict | None = None
-    ) -> None: ...
+    ) -> Self: ...
     def compress(
         self, /, data: ReadableBuffer, mode: _ZstdCompressorContinue | _ZstdCompressorFlushBlock | _ZstdCompressorFlushFrame = 0
     ) -> bytes: ...
@@ -58,7 +58,7 @@ class ZstdCompressor:
 
 @final
 class ZstdDecompressor:
-    def __init__(self, zstd_dict: ZstdDict | None = None, options: Mapping[int, int] | None = None) -> None: ...
+    def __new__(self, zstd_dict: ZstdDict | None = None, options: Mapping[int, int] | None = None) -> Self: ...
     def decompress(self, /, data: ReadableBuffer, max_length: int = -1) -> bytes: ...
     @property
     def eof(self) -> bool: ...
@@ -69,7 +69,7 @@ class ZstdDecompressor:
 
 @final
 class ZstdDict:
-    def __init__(self, dict_content: bytes, /, *, is_raw: bool = False) -> None: ...
+    def __new__(self, dict_content: bytes, /, *, is_raw: bool = False) -> Self: ...
     def __len__(self, /) -> int: ...
     @property
     def as_digested_dict(self) -> tuple[Self, int]: ...
diff --git a/stdlib/functools.pyi b/stdlib/functools.pyi
index e41eb4c2b65d..8b433e09e811 100644
--- a/stdlib/functools.pyi
+++ b/stdlib/functools.pyi
@@ -169,10 +169,17 @@ class partialmethod(Generic[_T]):
     func: Callable[..., _T] | _Descriptor
     args: tuple[Any, ...]
     keywords: dict[str, Any]
-    @overload
-    def __init__(self, func: Callable[..., _T], /, *args: Any, **keywords: Any) -> None: ...
-    @overload
-    def __init__(self, func: _Descriptor, /, *args: Any, **keywords: Any) -> None: ...
+    if sys.version_info >= (3, 14):
+        @overload
+        def __new__(self, func: Callable[..., _T], /, *args: Any, **keywords: Any) -> Self: ...
+        @overload
+        def __new__(self, func: _Descriptor, /, *args: Any, **keywords: Any) -> Self: ...
+    else:
+        @overload
+        def __init__(self, func: Callable[..., _T], /, *args: Any, **keywords: Any) -> None: ...
+        @overload
+        def __init__(self, func: _Descriptor, /, *args: Any, **keywords: Any) -> None: ...
+
     def __get__(self, obj: Any, cls: type[Any] | None = None) -> Callable[..., _T]: ...
     @property
     def __isabstractmethod__(self) -> bool: ...
diff --git a/stdlib/mmap.pyi b/stdlib/mmap.pyi
index 261a2bfdfc44..99a046a16229 100644
--- a/stdlib/mmap.pyi
+++ b/stdlib/mmap.pyi
@@ -33,7 +33,7 @@ PAGESIZE: Final[int]
 
 class mmap:
     if sys.platform == "win32":
-        def __init__(self, fileno: int, length: int, tagname: str | None = None, access: int = 0, offset: int = 0) -> None: ...
+        def __new__(self, fileno: int, length: int, tagname: str | None = None, access: int = 0, offset: int = 0) -> Self: ...
     else:
         if sys.version_info >= (3, 13):
             def __new__(