diff --git a/requirements.txt b/requirements.txt
index 6b8d2791..6727c478 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 Babel>=1.3
 pbr>=0.6,!=0.7,<1.0
 netaddr>=0.7.6
-oslo.i18n>=0.1.0
+oslo.i18n>=0.1.0  # Apache-2.0
 python-keystoneclient>=0.9.0
 requests>=1.1
 six>=1.7.0