diff --git a/Gemfile.lock b/Gemfile.lock
index 3f17ebd..c396c5d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -30,7 +30,7 @@ GEM
     minitest (5.11.3)
     multi_json (1.13.1)
     multi_test (0.1.2)
-    rack (1.6.9)
+    rack (1.6.13)
     rack-protection (1.2.0)
       rack
     rack-test (0.6.1)