1 files changed, 1 insertions, 0 deletions
diff --git a/tox.ini b/tox.ini
index 50a436e..c86609a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,6 @@
 [tox]
 envlist = py27,py34,py35,py36,py37,py38,pypy,pypy3
+isolated_build = True
 [testenv]
 changedir = {envtmpdir}
 deps=-r{toxinidir}/test-requirements.txt