diff --git a/requirements.txt b/requirements.txt
index a79ae26848..3fad10ef34 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -45,3 +45,4 @@ oslo.log>=3.11.0 # Apache-2.0
 oslo.db!=4.13.1,!=4.13.2,>=4.11.0 # Apache-2.0
 enum34;python_version=='2.7' or python_version=='2.6' or python_version=='3.3' # BSD
 xmltodict>=0.10.1 # MIT
+pycrypto>=2.6  # Public Domain