diff --git a/Chapter11/Exercise11.04/Gemfile.lock b/Chapter11/Exercise11.04/Gemfile.lock
index 6aee8a5..95e1d2e 100644
--- a/Chapter11/Exercise11.04/Gemfile.lock
+++ b/Chapter11/Exercise11.04/Gemfile.lock
@@ -100,7 +100,7 @@ GEM
       method_source (~> 0.9.0)
     public_suffix (4.0.1)
     puma (3.12.1)
-    rack (2.0.7)
+    rack (2.0.8)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
     rails (5.2.3)