diff --git a/python/tox.ini b/python/tox.ini
index ea4168177..0f1874afb 100644
--- a/python/tox.ini
+++ b/python/tox.ini
@@ -8,7 +8,7 @@ envlist =
 
 [testenv]
 commands = 
-    pytest -n6 --reruns 2 --reruns-delay 5 -v -rsXx --ignored --strict-tls {posargs: tests examples}
+    pytest -n1 --reruns 2 --reruns-delay 5 -v -rsXx --ignored --strict-tls {posargs: tests examples}
     python tests/package_wheels.py {toxworkdir}/wheelhouse
 passenv = 
     TRAVIS