diff --git a/Gemfile.lock b/Gemfile.lock
index 56a48b1..d68f658 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -47,7 +47,7 @@ GEM
     multi_json (1.10.1)
     pg (0.17.1)
     polyglot (0.3.5)
-    rack (1.5.2)
+    rack (1.5.5)
     rack-cors (0.3.1)
     rack-test (0.6.2)
       rack (>= 1.0)