diff --git a/test/sample_apps/rails4_app/Gemfile.lock b/test/sample_apps/rails4_app/Gemfile.lock
index 2b2c938..5c6794d 100644
--- a/test/sample_apps/rails4_app/Gemfile.lock
+++ b/test/sample_apps/rails4_app/Gemfile.lock
@@ -66,7 +66,7 @@ GEM
     nokogiri (1.9.1)
       mini_portile2 (~> 2.4.0)
     puma (3.12.0)
-    rack (1.6.11)
+    rack (1.6.13)
     rack-test (0.6.3)
       rack (>= 1.0)
     rails (4.2.11)