diff --git a/2019/s4/testing/Gemfile.lock b/2019/s4/testing/Gemfile.lock
index cd4f069..30939c7 100644
--- a/2019/s4/testing/Gemfile.lock
+++ b/2019/s4/testing/Gemfile.lock
@@ -105,7 +105,7 @@ GEM
       mini_portile2 (~> 2.4.0)
     public_suffix (4.0.1)
     puma (3.12.1)
-    rack (2.0.7)
+    rack (2.2.6.2)
     rack-proxy (0.6.5)
       rack
     rack-test (1.1.0)