diff --git a/Makefile b/Makefile
index d5f298d..00e2277 100644
--- a/Makefile
+++ b/Makefile
@@ -16,7 +16,8 @@ export DETERMINISTIC_TESTS := false
 export ETESYNC_TESTS := false
 
 # Assume to run in Travis. Don't use this outside of a virtual machine. It will
-# heavily "pollute" your system.
+# heavily "pollute" your system, such as attempting to install a new Python
+# systemwide.
 export CI := false
 
 # Whether to generate coverage data while running tests.
@@ -79,7 +80,7 @@ install-test: install-servers
 	[ -z "$(TEST_EXTRA_PACKAGES)" ] || pip install $(TEST_EXTRA_PACKAGES)
 
 install-style: install-docs
-	pip install flake8 flake8-import-order flake8-bugbear>=17.3.0
+	pip install flake8 flake8-import-order 'flake8-bugbear>=17.3.0' autopep8
 	
 style:
 	flake8
@@ -97,9 +98,6 @@ install-docs:
 docs:
 	cd docs && make html
 
-sh:  # open subshell with default test config
-	$$SHELL;
-
 linkcheck:
 	sphinx-build -W -b linkcheck ./docs/ ./docs/_build/linkcheck/
 
@@ -113,7 +111,7 @@ release-deb:
 	sh scripts/release-deb.sh ubuntu xenial
 	sh scripts/release-deb.sh ubuntu zesty
 
-install-dev:
+install-dev: install-git-hooks
 	pip install -e .
 	[ "$(ETESYNC_TESTS)" = "false" ] || pip install -e .[etesync]
 	set -xe && if [ "$(REQUIREMENTS)" = "devel" ]; then \
@@ -124,6 +122,13 @@ install-dev:
 		pip install -U --force-reinstall $$(python setup.py --quiet minimal_requirements); \
 	fi
 
+install-git-hooks: install-style
+	echo "make style-autocorrect" > .git/hooks/pre-commit
+	chmod +x .git/hooks/pre-commit
+
+style-autocorrect:
+	git diff --cached --name-only | egrep '\.py$$' | xargs --no-run-if-empty autopep8 -ri
+
 ssh-submodule-urls:
 	git submodule foreach "\
 		echo -n 'Old: '; \
diff --git a/docs/config.rst b/docs/config.rst
index 00b41f1..d6a47a9 100644
--- a/docs/config.rst
+++ b/docs/config.rst
@@ -174,9 +174,8 @@ To use this storage type, you need to install some additional dependencies::
     pip install vdirsyncer[google]
 
 Furthermore you need to register vdirsyncer as an application yourself to
-obtain ``client_id`` and ``client_secret``, as `it is against Google's Terms of
-Service to hardcode those into opensource software
-<https://developers.google.com/terms/?hl=th#b-confidential-matters>`_:
+obtain ``client_id`` and ``client_secret``, as it is against Google's Terms of
+Service to hardcode those into opensource software [googleterms]_:
 
 1. Go to the `Google API Manager <https://console.developers.google.com>`_ and
    create a new project under any name.
@@ -198,6 +197,9 @@ The ``token_file`` parameter should be a filepath where vdirsyncer can later
 store authentication-related data. You do not need to create the file itself
 or write anything to it.
 
+.. [googleterms] See `ToS <https://developers.google.com/terms/?hl=th>`_,
+   section "Confidential Matters".
+
 .. note::
 
     You need to configure which calendars Google should offer vdirsyncer using
diff --git a/docs/contributing.rst b/docs/contributing.rst
index 6d3b0fd..4c4adb0 100644
--- a/docs/contributing.rst
+++ b/docs/contributing.rst
@@ -79,19 +79,19 @@ For many patches, it might suffice to just let Travis run the tests. However,
 Travis is slow, so you might want to run them locally too. For this, set up a
 virtualenv_ and run this inside of it::
 
-    # install vdirsyncer from the repo into the virtualenv. Prerequisite for
-    # most other tasks.
+    # install:
+    #  - vdirsyncer from the repo into the virtualenv
+    #  - stylecheckers (flake8) and code formatters (autopep8)
+    #  - git commit hook for autopep8
     make install-dev
 
     make install-test  # install test dependencies
-    make install-style  # install dependencies for stylechecking
-    make install-docs  # install dependencies for building documentation
 
 Then you can run::
 
-    make test  # The normal testsuite
+    make test   # The normal testsuite
     make style  # Stylechecker
-    make docs  # Build the HTML docs, output is at docs/_build/html/
+    make docs   # Build the HTML docs, output is at docs/_build/html/
 
 The ``Makefile`` has a lot of options that allow you to control which tests are
 run, and which servers are tested. Take a look at its code where they are all
diff --git a/tests/storage/dav/__init__.py b/tests/storage/dav/__init__.py
index 2da3d8b..77109e8 100644
--- a/tests/storage/dav/__init__.py
+++ b/tests/storage/dav/__init__.py
@@ -17,7 +17,7 @@ from vdirsyncer.vobject import Item
 from .. import StorageTests, get_server_mixin
 
 
-dav_server = os.environ['DAV_SERVER']
+dav_server = os.environ.get('DAV_SERVER', 'skip')
 ServerMixin = get_server_mixin(dav_server)