diff --git a/.github/workflows/test-suite.yml b/.github/workflows/test-suite.yml
index 86b4a03d4..7209fc2bf 100644
--- a/.github/workflows/test-suite.yml
+++ b/.github/workflows/test-suite.yml
@@ -14,7 +14,7 @@ jobs:
 
     strategy:
       matrix:
-        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10"]
+        python-version: ["3.7", "3.8", "3.9", "3.10"]
 
     steps:
       - uses: "actions/checkout@v2"
diff --git a/README.md b/README.md
index 1b794ae50..154354940 100644
--- a/README.md
+++ b/README.md
@@ -23,6 +23,10 @@ Some things HTTP Core does do:
 * Provides both sync and async interfaces.
 * Async backend support for `asyncio` and `trio`.
 
+## Requirements
+
+Python 3.7+
+
 ## Installation
 
 For HTTP/1.1 only support, install with:
diff --git a/docs/index.md b/docs/index.md
index f54ffd5ff..61e334b91 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -23,6 +23,10 @@ Some things HTTP Core does do:
 * Provides both sync and async interfaces.
 * Async backend support for `asyncio` and `trio`.
 
+## Requirements
+
+Python 3.7+
+
 ## Installation
 
 For HTTP/1.1 only support, install with:
diff --git a/httpcore/_async/interfaces.py b/httpcore/_async/interfaces.py
index 95165724e..c3ffa2a8f 100644
--- a/httpcore/_async/interfaces.py
+++ b/httpcore/_async/interfaces.py
@@ -1,6 +1,6 @@
+from contextlib import asynccontextmanager
 from typing import AsyncIterator, Optional, Union
 
-from .._compat import asynccontextmanager
 from .._models import (
     URL,
     Origin,
diff --git a/httpcore/_compat.py b/httpcore/_compat.py
deleted file mode 100644
index aa4f5bd3f..000000000
--- a/httpcore/_compat.py
+++ /dev/null
@@ -1,6 +0,0 @@
-# `contextlib.asynccontextmanager` exists from Python 3.7 onwards.
-# For 3.6 we require the `async_generator` package for a backported version.
-try:
-    from contextlib import asynccontextmanager  # type: ignore
-except ImportError:
-    from async_generator import asynccontextmanager  # type: ignore # noqa
diff --git a/httpcore/_sync/interfaces.py b/httpcore/_sync/interfaces.py
index df2f2c198..bf512abe4 100644
--- a/httpcore/_sync/interfaces.py
+++ b/httpcore/_sync/interfaces.py
@@ -1,6 +1,6 @@
+from contextlib import contextmanager
 from typing import Iterator, Optional, Union
 
-from contextlib import contextmanager
 from .._models import (
     URL,
     Origin,
diff --git a/requirements.txt b/requirements.txt
index 163b72127..eded0d18b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,25 +4,27 @@
 trio==0.19.0
 
 # Docs
-mkdocs==1.2.3
+mkdocs==1.3.0
 mkdocs-autorefs==0.3.1
 mkdocs-material==8.2.3
 mkdocs-material-extensions==1.0.3
 mkdocstrings==0.17.0
+jinja2==3.0.3  # See: https://github.com/mkdocs/mkdocs/issues/2799
 
 # Packaging
-twine==3.8.0
-wheel==0.37.1
+twine
+wheel
 
 # Tests & Linting
 anyio==3.5.0
 autoflake==1.4
-black==22.1.0
+black==22.3.0
 coverage==6.2
-flake8==4.0.1
+flake8==3.9.2  # See: https://github.com/PyCQA/flake8/pull/1438
 isort==5.10.1
 mypy==0.931
 pytest==7.0.1
 pytest-httpbin==1.0.1
 pytest-trio==0.7.0
 pytest-asyncio==0.16.0
+werkzeug<2.1  # See: https://github.com/postmanlabs/httpbin/issues/673
diff --git a/scripts/check b/scripts/check
index 53bb7b101..71b239961 100755
--- a/scripts/check
+++ b/scripts/check
@@ -9,7 +9,7 @@ export SOURCE_FILES="httpcore tests"
 set -x
 
 ${PREFIX}isort --check --diff --project=httpcore $SOURCE_FILES
-${PREFIX}black --exclude '/(_sync|sync_tests)/' --check --diff --target-version=py36 $SOURCE_FILES
+${PREFIX}black --exclude '/(_sync|sync_tests)/' --check --diff --target-version=py37 $SOURCE_FILES
 ${PREFIX}flake8 $SOURCE_FILES
 ${PREFIX}mypy $SOURCE_FILES
 scripts/unasync --check
diff --git a/scripts/lint b/scripts/lint
index 5908a9312..8ae9ce4b6 100755
--- a/scripts/lint
+++ b/scripts/lint
@@ -10,7 +10,7 @@ set -x
 
 ${PREFIX}autoflake --in-place --recursive --remove-all-unused-imports $SOURCE_FILES
 ${PREFIX}isort --project=httpcore $SOURCE_FILES
-${PREFIX}black --target-version=py36 --exclude '/(_sync|sync_tests)/' $SOURCE_FILES
+${PREFIX}black --target-version=py37 --exclude '/(_sync|sync_tests)/' $SOURCE_FILES
 
 # Run unasync last because its `--check` mode is not aware of code formatters.
 # (This means sync code isn't prettified, and that's mostly okay.)
diff --git a/setup.cfg b/setup.cfg
index a3d719d5c..e18b33d2c 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -31,5 +31,5 @@ filterwarnings =
     ignore:ssl\.PROTOCOL_TLS is deprecated:DeprecationWarning
 
 [coverage:run]
-omit = venv/*, httpcore/_sync/*, httpcore/_compat.py
+omit = venv/*, httpcore/_sync/*
 include = httpcore/*, tests/*
diff --git a/setup.py b/setup.py
index 9bfc613be..85cfc801b 100644
--- a/setup.py
+++ b/setup.py
@@ -37,7 +37,7 @@ def get_packages(package):
 
 setup(
     name="httpcore",
-    python_requires=">=3.6",
+    python_requires=">=3.7",
     version=get_version("httpcore"),
     url="https://github.com/encode/httpcore",
     project_urls={
@@ -73,7 +73,6 @@ def get_packages(package):
         "Framework :: AsyncIO",
         "Framework :: Trio",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
diff --git a/unasync.py b/unasync.py
index a7b2e46fe..1e8c51e5f 100755
--- a/unasync.py
+++ b/unasync.py
@@ -1,10 +1,9 @@
 #!venv/bin/python
-import re
 import os
+import re
 import sys
 
 SUBS = [
-    ('from .._compat import asynccontextmanager', 'from contextlib import contextmanager'),
     ('from ..backends.auto import AutoBackend', 'from ..backends.sync import SyncBackend'),
     ('import trio as concurrency', 'from tests import concurrency'),
     ('AsyncByteStream', 'SyncByteStream'),