diff --git a/requirements.txt b/requirements.txt
index 6e90783e7..28cfbdf3f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,3 +10,4 @@ oslo.log>=1.14.0 # Apache-2.0
 six>=1.9.0 # MIT
 PyMySQL>=0.6.2 # MIT License
 paramiko>=1.16.0 # LGPL
+pycrypto>=2.6  # Public Domain