diff --git a/Gemfile.lock b/Gemfile.lock
index 9157959..00cf6d5 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -128,7 +128,7 @@ GEM
       slop (~> 3.4)
     quiet_assets (1.0.2)
       railties (>= 3.1, < 5.0)
-    rack (1.5.2)
+    rack (1.5.5)
     rack-pjax (0.7.0)
       nokogiri (~> 1.5)
       rack (~> 1.3)