diff --git a/demo_app/Gemfile.lock b/demo_app/Gemfile.lock
index 2bb7a8a..aa087e8 100644
--- a/demo_app/Gemfile.lock
+++ b/demo_app/Gemfile.lock
@@ -106,7 +106,7 @@ GEM
       mini_portile2 (~> 2.4.0)
     public_suffix (4.0.1)
     puma (3.12.1)
-    rack (2.0.7)
+    rack (2.2.3)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
     rails (5.2.3)