diff --git a/Gemfile.lock b/Gemfile.lock
index 9d480ed..45d2277 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -100,7 +100,7 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.8.1)
       slop (~> 3.4)
-    rack (1.5.2)
+    rack (1.5.5)
     rack-test (0.6.3)
       rack (>= 1.0)
     rails (4.1.10)