1 files changed, 1 insertions, 1 deletions
diff --git a/tox.ini b/tox.ini
index 1107e6c..88f00db 100644
--- a/tox.ini
+++ b/tox.ini
@@ -10,7 +10,7 @@ setenv = VIRTUAL_ENV={envdir}
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands =
-  python setup.py testr --slowest --testr-args='{posargs}'
+  python setup.py testr --slowest --testr-args='{posargs} --concurrency=1'
 
 [testenv:py26sa07]
 basepython = python2.6