diff --git a/Gemfile.lock b/Gemfile.lock
index 7a6a73c..92ffacf 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -29,7 +29,7 @@ GEM
     multi_json (1.15.0)
     mustermann (3.0.0)
       ruby2_keywords (~> 0.0.1)
-    rack (2.2.4)
+    rack (2.2.6.3)
     rack-protection (3.0.4)
       rack
     redis (4.2.1)