diff --git a/Gemfile.lock b/Gemfile.lock
index ee83b68..fe95b1e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -106,7 +106,7 @@ GEM
     phantomjs (1.9.7.1)
     puma (2.8.2)
       rack (>= 1.1, < 2.0)
-    rack (1.5.2)
+    rack (1.5.5)
     rack-protection (1.5.3)
       rack
     rack-test (0.6.3)