diff --git a/tox.ini b/tox.ini
index 7c339d0ee0..93d8f18601 100644
--- a/tox.ini
+++ b/tox.ini
@@ -23,7 +23,8 @@ commands =
 downloadcache = ~/cache/pip
 
 [testenv:cover]
-setenv = NOSE_WITH_COVERAGE=1
+setenv = VIRTUAL_ENV={envdir}
+         NOSE_WITH_COVERAGE=1
          NOSE_COVER_HTML=1
          NOSE_COVER_HTML_DIR={toxinidir}/cover