diff --git a/Gemfile.lock b/Gemfile.lock
index c55beda..049d925 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -37,7 +37,7 @@ GEM
     puma (4.3.1)
       nio4r (~> 2.0)
     racc (1.6.2)
-    rack (2.0.7)
+    rack (2.1.4.2)
     redis (3.0.2)
     rspec (2.12.0)
       rspec-core (~> 2.12.0)