Add explicit tests for pytest{2,3,4}
diff --git a/README.rst b/README.rst
index cee5550..9014bc1 100644
--- a/README.rst
+++ b/README.rst
@@ -233,6 +233,13 @@
      - yes
      - yes
 
+*Note*: py.test 4 is `not yet supported`__ (but coming!), and py.test 2 under
+Python 3 `does not appear to work`__. Please comment on the related issues if
+you are affected.
+
+__ https://github.com/wolever/parameterized/issues/34
+__ https://github.com/wolever/parameterized/issues/71
+
 Dependencies
 ------------
 
diff --git a/tox.ini b/tox.ini
index fd5bee2..93c0656 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,15 +1,19 @@
 [tox]
-envlist=py{27,35,36,37,py}-{nose,nose2,pytest,unit,unit2} 
+envlist=py{27,35,36,py}-{nose,nose2,pytest2,pytest3,unit,unit2},py37-{nose,nose2,pytest3,unit,unit2}
 [testenv]
 deps=
     nose
     mock
     nose2: nose2
-    pytest: pytest>=2,<3
+    pytest2: pytest>=2,<3
+    pytest3: pytest>=3,<4
+    #pytest4: pytest>=4,<5
     unit2: unittest2
 commands=
     nose: nosetests
     nose2: nose2
-    pytest: py.test parameterized/test.py
+    pytest2: py.test parameterized/test.py
+    pytest3: py.test parameterized/test.py
+    #pytest4: py.test parameterized/test.py
     unit: python -m unittest parameterized.test
     unit2: unit2 parameterized.test