diff --git a/tox.ini b/tox.ini
index 9d0ee7b8..96e24276 100644
--- a/tox.ini
+++ b/tox.ini
@@ -36,21 +36,21 @@ deps =
      MySQL-python
      pycurl
      simplejson
-     twisted
+     twisted==11.0.0
 
 [testenv:py26-full]
 basepython = python2.6
 deps =
      MySQL-python
      pycurl
-     twisted
+     twisted==11.0.0
 
 [testenv:py27-full]
 basepython = python2.7
 deps =
      MySQL-python
      pycurl
-     twisted
+     twisted==11.0.0
 
 # No pypy-full yet: pycurl doesn't build with pypy, and installing
 # twisted under pypy takes a *very* long time.  MySQL-python builds with