diff --git a/Gemfile.lock b/Gemfile.lock
index 764f6a1..f563f29 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -59,7 +59,7 @@ GEM
     minitest (5.8.1)
     nokogiri (1.6.6.2)
       mini_portile (~> 0.6.0)
-    rack (1.6.4)
+    rack (1.6.13)
     rack-cors (0.4.0)
     rack-test (0.6.3)
       rack (>= 1.0)