diff --git a/requirements.txt b/requirements.txt
index 9f6359b63..0444e0bb5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,6 +4,7 @@
 
 pbr>=2.0.0 # Apache-2.0
 Babel>=2.3.4 # BSD
+itsdangerous<2.1 # BSD
 Flask!=0.11,<1.0,>=0.10 # BSD
 iso8601>=0.1.11 # MIT
 jsonschema>=2.0.0,<3.0.0,!=2.5.0 # MIT