diff --git a/etc/requirements_dev.txt b/etc/requirements_dev.txt
index b989cafd..96d9f29d 100644
--- a/etc/requirements_dev.txt
+++ b/etc/requirements_dev.txt
@@ -24,7 +24,7 @@ mistune==0.5.1
 
 # Required by tornado
 backports.ssl-match-hostname==3.4.0.2;python_version<'3.0'
-certifi==14.5.14
+certifi==2015.4.28
 
 # tornado and pyparsing are required by matplotlib
 tornado==4.1