diff --git a/Gemfile.lock b/Gemfile.lock
index f3cb1b6..739f436 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -82,7 +82,7 @@ GEM
       coderay (~> 1.0.5)
       method_source (~> 0.8)
       slop (~> 3.4)
-    rack (1.5.2)
+    rack (1.5.5)
     rack-test (0.6.2)
       rack (>= 1.0)
     rails (4.0.0)