diff --git a/requirements.txt b/requirements.txt
index ee5358640..688fa36d2 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -14,7 +14,7 @@ statsd==3.3.0
 xxhash==2.0.2
 objgraph==3.5.0
 zerorpc==0.6.3
-cssutils==2.3.1
+cssutils==2.15.0
 tinycss2==1.1.1
 fontTools==4.27.1
 fdict==0.8.1