diff --git a/requirements.txt b/requirements.txt
index 8ba92bf..13e29e6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,4 +4,5 @@
 
 dnspython!=1.13.0,>=1.12.0;python_version<'3.0' # http://www.dnspython.org/LICENSE
 dnspython3>=1.12.0;python_version>='3.0' # http://www.dnspython.org/LICENSE
+ddt>=1.0.1  # MIT
 tempest>=11.0.0 # Apache-2.0