diff --git a/.github/workflows/python.yml b/.github/workflows/python.yml
index ca6727c..8f6da92 100644
--- a/.github/workflows/python.yml
+++ b/.github/workflows/python.yml
@@ -26,7 +26,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: "3.9"
+          python-version: "3.10"
 
       - name: Install core Python packages
         run: python -m pip install --upgrade pip setuptools build 
@@ -58,7 +58,6 @@ jobs:
       fail-fast: false
       matrix:
         python:
-          - {version: '3.9'}
           - {version: '3.10'}
           - {version: '3.11'}
           - {version: '3.12'}
diff --git a/pyproject.toml b/pyproject.toml
index b368408..5d80fa2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -13,12 +13,12 @@ authors = [
 description = "An open source randomizer patcher for Metroid Fusion."
 readme = "README.md"
 license = {file = "LICENSE"}
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 classifiers = [
     "Programming Language :: Python :: 3",
     "License :: OSI Approved :: GNU General Public License v3 (GPLv3)",
     "Development Status :: 3 - Alpha",
-    "Programming Language :: Python :: 3.9"
+    "Programming Language :: Python :: 3.10"
 
 ]
 dependencies = [
diff --git a/src/mars_patcher/common_types.py b/src/mars_patcher/common_types.py
index 6be881b..823298b 100644
--- a/src/mars_patcher/common_types.py
+++ b/src/mars_patcher/common_types.py
@@ -1,6 +1,4 @@
-from typing import Annotated
-
-from typing_extensions import TypeAlias
+from typing import Annotated, TypeAlias
 
 from mars_patcher.auto_generated_types import Areaid, Typeu8
 
diff --git a/src/mars_patcher/patcher.py b/src/mars_patcher/patcher.py
index 66ccb28..6a9cfe8 100644
--- a/src/mars_patcher/patcher.py
+++ b/src/mars_patcher/patcher.py
@@ -1,7 +1,7 @@
 import json
 import typing
+from collections.abc import Callable
 from os import PathLike
-from typing import Callable, Union
 
 from jsonschema import validate
 
@@ -46,12 +46,12 @@ def validate_patch_data(patch_data: dict) -> MarsSchema:
     with open(get_data_path("schema.json")) as f:
         schema = json.load(f)
     validate(patch_data, schema)
-    return typing.cast(MarsSchema, patch_data)
+    return typing.cast("MarsSchema", patch_data)
 
 
 def patch(
-    input_path: Union[str, PathLike[str]],
-    output_path: Union[str, PathLike[str]],
+    input_path: str | PathLike[str],
+    output_path: str | PathLike[str],
     patch_data: MarsSchema,
     status_update: Callable[[str, float], None],
 ) -> None:
diff --git a/src/mars_patcher/rom.py b/src/mars_patcher/rom.py
index f20ef60..f08d309 100644
--- a/src/mars_patcher/rom.py
+++ b/src/mars_patcher/rom.py
@@ -1,10 +1,9 @@
 from enum import Enum
 from os import PathLike
-from typing import Union
 
 from mars_patcher.constants.reserved_space import ReservedConstants
 
-BytesLike = Union[bytes, bytearray]
+BytesLike = bytes | bytearray
 
 SIZE_8MB = 0x800000
 ROM_OFFSET = 0x8000000
@@ -82,7 +81,7 @@ class Rom:
         },
     }
 
-    def __init__(self, path: Union[str, PathLike[str]]):
+    def __init__(self, path: str | PathLike[str]):
         # Read file
         with open(path, "rb") as f:
             self.data = bytearray(f.read())
@@ -238,7 +237,7 @@ def reserve_free_space(self, size: int) -> int:
             raise RuntimeError("Ran out of reserved free space")
         return addr
 
-    def save(self, path: Union[str, PathLike[str]]) -> None:
+    def save(self, path: str | PathLike[str]) -> None:
         """Saves the currently loaded data to a specified path."""
         with open(path, "wb") as f:
             f.write(self.data)