diff --git a/requirements.txt b/requirements.txt
index 9e16833..8721b2c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,4 +2,4 @@ numpy>=1.10.0,<2
 promise>=2.1,<3
 six>=1.10.0,<2
 requests>=2.19.0,<3  # will not work below in python3
-tenacity>=5.1,<6
+tenacity>=5.1,<9