diff --git a/Gemfile.lock b/Gemfile.lock
index d64ac747a..2437dfe3e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -122,7 +122,7 @@ GEM
     connection_pool (2.4.1)
     content_disposition (1.0.0)
     crass (1.0.6)
-    css_parser (1.14.0)
+    css_parser (1.15.0)
       addressable
     date (3.3.3)
     diff-lcs (1.5.0)