diff --git a/Gemfile.lock b/Gemfile.lock
index 86c1ebe..f8a35d6 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -121,7 +121,7 @@ GEM
     pry-stack_explorer (0.4.9.1)
       binding_of_caller (>= 0.7)
       pry (>= 0.9.11)
-    rack (1.5.2)
+    rack (1.5.5)
     rack-contrib (1.1.0)
       rack (>= 0.9.1)
     rack-test (0.6.2)