diff --git a/setup.py b/setup.py
index 74f729dd..c203ef55 100644
--- a/setup.py
+++ b/setup.py
@@ -27,7 +27,7 @@ def get_version():
 install_requires = [
     'lxml>=2.3',
     'python-dateutil',
-    'cybox>=2.1.0.13.dev1,<2.1.1.0',
+    'cybox>=2.1.0.17,<2.1.1.0',
     'mixbox>=1.0.2',
 ]