diff --git a/.github/workflows/python-lint.yml b/.github/workflows/python-lint.yml
index 811bb548..f7d9d0cd 100644
--- a/.github/workflows/python-lint.yml
+++ b/.github/workflows/python-lint.yml
@@ -6,17 +6,17 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
-    - uses: actions/setup-python@v2
+    - uses: actions/checkout@v4
+    - uses: actions/setup-python@v5
       with:
-        python-version: "3.11"
+        python-version: "3.12"
     - uses: isort/isort-action@master
       with:
         sortPaths: "./mautrix_telegram"
     - uses: psf/black@stable
       with:
         src: "./mautrix_telegram"
-        version: "23.1.0"
+        version: "23.11.0"
     - name: pre-commit
       run: |
         pip install pre-commit
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a417b4ab..41445e71 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+# unreleased
+
+* Dropped support for Python 3.9.
+* Updated Telegram API to layer 170.
+
 # v0.15.1 (2023-12-26)
 
 * Updated Telegram API to layer 169.
diff --git a/requirements.txt b/requirements.txt
index 924149b9..832c6e99 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,8 +3,8 @@ python-magic>=0.4,<0.5
 commonmark>=0.8,<0.10
 aiohttp>=3,<4
 yarl>=1,<2
-mautrix>=0.20.3,<0.21
-tulir-telethon==1.34.0a2
+mautrix>=0.20.4,<0.21
+tulir-telethon==1.34.0a3
 asyncpg>=0.20,<0.30
 mako>=1,<2
 setuptools
diff --git a/setup.py b/setup.py
index 6321cdbe..94a23aae 100644
--- a/setup.py
+++ b/setup.py
@@ -51,7 +51,7 @@ setuptools.setup(
 
     install_requires=install_requires,
     extras_require=extras_require,
-    python_requires="~=3.9",
+    python_requires="~=3.10",
 
     classifiers=[
         "Development Status :: 4 - Beta",
@@ -60,7 +60,6 @@ setuptools.setup(
         "Framework :: AsyncIO",
         "Programming Language :: Python",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",