diff --git a/requirements/python/tests.txt b/requirements/python/tests.txt
index 8efba24..4237572 100644
--- a/requirements/python/tests.txt
+++ b/requirements/python/tests.txt
@@ -1,5 +1,5 @@
 # latest version to validate behavior on pure python env
-pytest
+pytest==3.4.0
 pytest-xdist  # for --boxed
 hypothesis
 numpy