diff --git a/requirements/tests.txt b/requirements/tests.txt
index 4451d4f..78c5224 100644
--- a/requirements/tests.txt
+++ b/requirements/tests.txt
@@ -1,5 +1,5 @@
 # latest version to validate behavior on pure python env
 pytest
 # pytest-xdist  # for --boxed  # dropping this because of compat req with six...
-hypothesis
+hypothesis==3.56.0
 numpy