diff --git a/CHANGELOG.md b/CHANGELOG.md
index f40360f..15fa32b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,6 +30,7 @@ This project has adhered to
 
 - Fix a reference leak in the `hash_from_buffer()` function
   ([#75](https://github.com/hajimes/mmh3/issues/75)).
+- Fix type hints.
 
 ## [4.1.0] - 2024-01-09
 
diff --git a/README.md b/README.md
index adbf8fc..1074efc 100644
--- a/README.md
+++ b/README.md
@@ -155,6 +155,7 @@ complete changelog.
 
 - Fix a reference leak in the `hash_from_buffer()` function
   ([#75](https://github.com/hajimes/mmh3/issues/75)).
+- Fix type hints.
 
 ### [4.1.0] - 2024-01-09
 
diff --git a/src/mmh3/__init__.pyi b/src/mmh3/__init__.pyi
index 5edddf8..3243420 100644
--- a/src/mmh3/__init__.pyi
+++ b/src/mmh3/__init__.pyi
@@ -1,40 +1,52 @@
 # to use list, tuple, dict ... in Python 3.7 and 3.8
 from __future__ import annotations
 
-from typing import Protocol, Union, final
+from typing import TYPE_CHECKING, Union, final
 
-class IntArrayLike(Protocol):
-    def __getitem__(self, index) -> int: ...
+if TYPE_CHECKING:
+    from _typeshed import ReadableBuffer
 
-Hashable = Union[bytes, bytearray, memoryview, IntArrayLike]
-StrHashable = Union[str, Hashable]
+HashableImmutable = Union[str, bytes]
+HashableBuffer = Union[HashableImmutable, ReadableBuffer]
 
-def hash(key: StrHashable, seed: int = 0, signed: bool = True) -> int: ...
-def hash_from_buffer(key: StrHashable, seed: int = 0, signed: bool = True) -> int: ...
+def hash(key: HashableImmutable, seed: int = 0, signed: bool = True) -> int: ...
+def hash_from_buffer(
+    key: HashableBuffer, seed: int = 0, signed: bool = True
+) -> int: ...
 def hash64(
-    key: StrHashable, seed: int = 0, x64arch: bool = True, signed: bool = True
+    key: HashableImmutable, seed: int = 0, x64arch: bool = True, signed: bool = True
 ) -> tuple[int, int]: ...
 def hash128(
-    key: StrHashable, seed: int = 0, x64arch: bool = True, signed: bool = False
+    key: HashableImmutable, seed: int = 0, x64arch: bool = True, signed: bool = False
 ) -> int: ...
-def hash_bytes(key: StrHashable, seed: int = 0, x64arch: bool = True) -> bytes: ...
-def mmh3_32_digest(key: StrHashable, seed: int = 0) -> bytes: ...
-def mmh3_32_sintdigest(key: StrHashable, seed: int = 0) -> int: ...
-def mmh3_32_uintdigest(key: StrHashable, seed: int = 0) -> int: ...
-def mmh3_x64_128_digest(key: StrHashable, seed: int = 0) -> bytes: ...
-def mmh3_x64_128_sintdigest(key: StrHashable, seed: int = 0) -> int: ...
-def mmh3_x64_128_uintdigest(key: StrHashable, seed: int = 0) -> int: ...
-def mmh3_x64_128_stupledigest(key: StrHashable, seed: int = 0) -> tuple[int, int]: ...
-def mmh3_x64_128_utupledigest(key: StrHashable, seed: int = 0) -> tuple[int, int]: ...
-def mmh3_x86_128_digest(key: StrHashable, seed: int = 0) -> bytes: ...
-def mmh3_x86_128_sintdigest(key: StrHashable, seed: int = 0) -> int: ...
-def mmh3_x86_128_uintdigest(key: StrHashable, seed: int = 0) -> int: ...
-def mmh3_x86_128_stupledigest(key: StrHashable, seed: int = 0) -> tuple[int, int]: ...
-def mmh3_x86_128_utupledigest(key: StrHashable, seed: int = 0) -> tuple[int, int]: ...
+def hash_bytes(
+    key: HashableImmutable, seed: int = 0, x64arch: bool = True
+) -> bytes: ...
+def mmh3_32_digest(key: HashableBuffer, seed: int = 0) -> bytes: ...
+def mmh3_32_sintdigest(key: HashableBuffer, seed: int = 0) -> int: ...
+def mmh3_32_uintdigest(key: HashableBuffer, seed: int = 0) -> int: ...
+def mmh3_x64_128_digest(key: HashableBuffer, seed: int = 0) -> bytes: ...
+def mmh3_x64_128_sintdigest(key: HashableBuffer, seed: int = 0) -> int: ...
+def mmh3_x64_128_uintdigest(key: HashableBuffer, seed: int = 0) -> int: ...
+def mmh3_x64_128_stupledigest(
+    key: HashableBuffer, seed: int = 0
+) -> tuple[int, int]: ...
+def mmh3_x64_128_utupledigest(
+    key: HashableBuffer, seed: int = 0
+) -> tuple[int, int]: ...
+def mmh3_x86_128_digest(key: HashableBuffer, seed: int = 0) -> bytes: ...
+def mmh3_x86_128_sintdigest(key: HashableBuffer, seed: int = 0) -> int: ...
+def mmh3_x86_128_uintdigest(key: HashableBuffer, seed: int = 0) -> int: ...
+def mmh3_x86_128_stupledigest(
+    key: HashableBuffer, seed: int = 0
+) -> tuple[int, int]: ...
+def mmh3_x86_128_utupledigest(
+    key: HashableBuffer, seed: int = 0
+) -> tuple[int, int]: ...
 
 class Hasher:
     def __init__(self, seed: int = 0) -> None: ...
-    def update(self, input: Hashable) -> None: ...
+    def update(self, input: ReadableBuffer) -> None: ...
     def digest(self) -> bytes: ...
     def sintdigest(self) -> int: ...
     def uintdigest(self) -> int: ...