diff --git a/Gemfile.lock b/Gemfile.lock
index 2a3e248..4dbc6d2 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -62,7 +62,7 @@ GEM
     minitest (5.4.3)
     multi_json (1.10.1)
     polyglot (0.3.5)
-    rack (1.5.2)
+    rack (1.5.5)
     rack-test (0.6.2)
       rack (>= 1.0)
     rails (4.1.4)