diff --git a/.travis.yml b/.travis.yml
index d710d11..7a10e06 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,8 +6,8 @@ python:
   - "3.5"
   - "3.6"
   - pypy
+  - pypy3
 install:
-  - pip install --upgrade pytest
   - pip install -r requirements-travis.txt
   - pip install -e .
 script: pytest
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 4e197a9..4381487 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,9 +1,9 @@
 -r requirements-travis.txt
+
 # test tools
-pytest
 tox
 
 # documentation
-Pygments>=1.6
+Pygments >= 1.6
 Sphinx
 sphinx_rtd_theme
diff --git a/requirements-travis.txt b/requirements-travis.txt
index 80be0ce..cfc7872 100644
--- a/requirements-travis.txt
+++ b/requirements-travis.txt
@@ -1,3 +1,5 @@
+pytest >= 3.2.1
+
 # code quality
 flake8
 coverage
diff --git a/tox.ini b/tox.ini
index 8d38373..1f5be88 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,pypy,py34,py35,py36,flake8
+envlist = py27,pypy,py34,py35,py36,pypy3,flake8
 skipsdist = True
 
 [testenv]