diff --git a/Gemfile.lock b/Gemfile.lock
index a4d6f8f8..cd86bada 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -79,7 +79,7 @@ GEM
     minitest (5.11.1)
     nokogiri (1.8.1)
       mini_portile2 (~> 2.3.0)
-    rack (1.6.8)
+    rack (1.6.13)
     rack-cors (0.4.0)
     rack-test (0.6.3)
       rack (>= 1.0)