1 files changed, 9 insertions, 2 deletions
diff --git a/tox.ini b/tox.ini
index 892684d..8f10b15 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,8 +1,15 @@
 [tox]
-envlist = py26,py27,py32,py33,py34,pypy,pypy3
+envlist = {py26,py27,py32,py33,py34}-{c,pure},{pypy,pypy3}-pure
+
+[variants:pure]
+setenv=
+    MSGPACK_PUREPYTHON=x
 
 [testenv]
 deps=
     pytest
 
-commands=py.test test
+changedir=test
+commands=
+    c: python -c 'from msgpack import _packer, _unpacker' && py.test
+    pure: py.test