diff --git a/Gemfile.lock b/Gemfile.lock
index ed5957e..ba45e56 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -32,7 +32,7 @@ GEM
     i18n (0.7.0)
     json (1.8.3)
     minitest (5.8.0)
-    rack (1.6.1)
+    rack (1.6.4)
     rack-protection (1.5.3)
       rack
     rack-test (0.6.3)