diff --git a/etc/requirements.txt b/etc/requirements.txt
index c09ae09b..fd757aa5 100644
--- a/etc/requirements.txt
+++ b/etc/requirements.txt
@@ -26,7 +26,7 @@ six==1.9.0
 # For fetching remote data
 requests==2.9.1
 
-Cython==0.23.4
+Cython==0.22.1
 
 # faster OrderedDict
 cyordereddict==0.2.2