diff --git a/Gemfile.lock b/Gemfile.lock
index 51d994c..81dd037 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -14,7 +14,7 @@ GEM
       mime-types (>= 1.16, < 3)
     mime-types (2.6.2)
     minitest (5.8.1)
-    rack (1.6.4)
+    rack (1.6.13)
     rake (10.4.2)
     thin (1.6.4)
       daemons (~> 1.0, >= 1.0.9)