diff --git a/tox.ini b/tox.ini
index 73e43cf..95c9796 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,49 +4,59 @@ envlist=py25-1.1,py25-1.2,py25,py25-trunk,py26-1.1,py26-1.2,py26,py26-trunk,py27
 [testenv]
 deps=
   django==1.3
+  South==0.7.3
 commands=python setup.py test
 
 [testenv:py25-1.1]
 basepython=python2.5
 deps=
   django==1.1.4
+  South==0.7.3
 
 [testenv:py25-1.2]
 basepython=python2.5
 deps=
   django==1.2.5
+  South==0.7.3
 
 [testenv:py25-trunk]
 basepython=python2.5
 deps=
   svn+http://code.djangoproject.com/svn/django/trunk#egg=django
+  South==0.7.3
 
 [testenv:py26-1.1]
 basepython=python2.6
 deps=
   django==1.1.4
+  South==0.7.3
 
 [testenv:py26-1.2]
 basepython=python2.6
 deps=
   django==1.2.5
+  South==0.7.3
 
 [testenv:py26-trunk]
 basepython=python2.6
 deps=
   svn+http://code.djangoproject.com/svn/django/trunk#egg=django
+  South==0.7.3
 
 [testenv:py27-1.1]
 basepython=python2.7
 deps=
   django==1.1.4
+  South==0.7.3
 
 [testenv:py27-1.2]
 basepython=python2.7
 deps=
   django==1.2.5
+  South==0.7.3
 
 [testenv:py27-trunk]
 basepython=python2.7
 deps=
   svn+http://code.djangoproject.com/svn/django/trunk#egg=django
+  South==0.7.3