diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 59dc3f8..8400c95 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -2,22 +2,17 @@
     sha: 003e43251aea1da33f2072f2365ec8b9ceaae070
     hooks:
     -   id: autopep8-wrapper
-        language_version: python2.7
     -   id: check-added-large-files
     -   id: check-docstring-first
-        language_version: python2.7
     -   id: check-json
     -   id: check-merge-conflict
     -   id: check-xml
     -   id: check-yaml
     -   id: debug-statements
-        language_version: python2.7
     -   id: detect-private-key
     -   id: double-quote-string-fixer
-        language_version: python2.7
     -   id: end-of-file-fixer
     -   id: flake8
-        language_version: python2.7
     -   id: name-tests-test
         exclude: ^tests/lib
     -   id: requirements-txt-fixer
@@ -26,7 +21,6 @@
     sha: 3d86483455ab5bd06cc1069fdd5ac57be5463f10
     hooks:
     -   id: reorder-python-imports
-        language_version: python2.7
 -   repo: https://github.com/Lucas-C/pre-commit-hooks.git
     sha: 181a63c511691da58116fa19a7241956018660bc
     hooks:
diff --git a/CI/circle b/CI/circle
index 11652c7..1d6e4aa 100755
--- a/CI/circle
+++ b/CI/circle
@@ -21,6 +21,7 @@ TARGETS = [
     'itest_wheezy',
     'itest_jessie',
     'itest_stretch',
+    'itest_tox',
 ]
 
 
diff --git a/Makefile b/Makefile
index 2a063d6..f473784 100644
--- a/Makefile
+++ b/Makefile
@@ -2,11 +2,12 @@ CFLAGS=-std=gnu99 -static -Wall -Werror -O3
 
 TEST_PACKAGE_DEPS := python python-pip
 
-DOCKER_RUN_TEST := docker run -v $(PWD):/mnt:ro
+DOCKER_RUN_TEST := docker run -ti -v $(PWD):/mnt:ro
+
+# test installation using Debian packages
 DOCKER_DEB_TEST := sh -euxc ' \
 	apt-get update \
 	&& apt-get install -y --no-install-recommends $(TEST_PACKAGE_DEPS) \
-	&& (which timeout || apt-get install -y --no-install-recommends timeout) \
 	&& dpkg -i /mnt/dist/*.deb \
 	&& tmp=$$(mktemp -d) \
 	&& cp -r /mnt/* "$$tmp" \
@@ -15,10 +16,11 @@ DOCKER_DEB_TEST := sh -euxc ' \
 	&& py.test tests/ \
 	&& exec dumb-init /mnt/tests/test-zombies \
 '
+
+# test installation using `pip install`
 DOCKER_PYTHON_TEST := sh -uexc ' \
 	apt-get update \
 	&& apt-get install -y --no-install-recommends python-pip build-essential $(TEST_PACKAGE_DEPS) \
-	&& (which timeout || apt-get install -y --no-install-recommends timeout) \
 	&& tmp=$$(mktemp -d) \
 	&& cp -r /mnt/* "$$tmp" \
 	&& cd "$$tmp" \
@@ -30,6 +32,17 @@ DOCKER_PYTHON_TEST := sh -uexc ' \
 	&& exec dumb-init /mnt/tests/test-zombies \
 '
 
+# test several Python versions using tox
+DOCKER_TOX_TEST := sh -uexc ' \
+	apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 0x5BB92C09DB82666C \
+	&& echo "deb http://ppa.launchpad.net/fkrull/deadsnakes/ubuntu trusty main" >> /etc/apt/sources.list \
+	&& apt-get update \
+	&& apt-get install -y --no-install-recommends python2.6 python2.7 python3.4 python-tox build-essential git $(TEST_PACKAGE_DEPS) \
+	&& tmp=$$(mktemp -du) \
+	&& cp -r /mnt "$$tmp" \
+	&& cd "$$tmp" \
+	&& tox \
+'
 .PHONY: build
 build:
 	$(CC) $(CFLAGS) -o dumb-init dumb-init.c
@@ -74,6 +87,9 @@ itest_wheezy: _itest-debian-wheezy
 itest_jessie: _itest-debian-jessie
 itest_stretch: _itest-debian-stretch
 
+itest_tox:
+	$(DOCKER_RUN_TEST) ubuntu:trusty $(DOCKER_TOX_TEST)
+
 _itest-%: _itest_deb-% _itest_python-%
 	@true
 
diff --git a/tests/tty_test.py b/tests/tty_test.py
index 65d9959..9b33965 100644
--- a/tests/tty_test.py
+++ b/tests/tty_test.py
@@ -12,15 +12,6 @@ def ttyflags(fd):
     T.tcsetattr(fd, T.TCSANOW, attrs)
 
 
-def tac():
-    """
-    run tac. if it fails to complete in 1 second send SIGKILL and exit with an
-    error.
-    """
-    from os import execvp
-    execvp('timeout', ('timeout', '1', 'dumb-init', 'tac'))
-
-
 def readall(fd):
     """read until EOF"""
     from os import read
@@ -58,6 +49,7 @@ def test_tty(debug_disabled):
     import pty
     pid, fd = pty.fork()
     if pid == 0:
-        tac()
+        from os import execvp
+        execvp('dumb-init', ('dumb-init', 'tac'))
     else:
         _test(fd)
diff --git a/tox.ini b/tox.ini
index e778639..8f94ee6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,8 +1,8 @@
 [tox]
-envlist = py27,py34
+envlist = py26,py27,py34
 
 [testenv]
-deps = -rrequirements-dev.txt
+deps = -r{toxinidir}/requirements-dev.txt
 commands =
     python -m pytest
     pre-commit run --all-files