diff --git a/examples/swagger_demo/doc/Gemfile.lock b/examples/swagger_demo/doc/Gemfile.lock
index 2c5e005..9b2a16b 100644
--- a/examples/swagger_demo/doc/Gemfile.lock
+++ b/examples/swagger_demo/doc/Gemfile.lock
@@ -89,7 +89,7 @@ GEM
       activesupport (>= 3.1)
     parallel (1.10.0)
     public_suffix (4.0.6)
-    rack (2.2.3)
+    rack (2.2.8.1)
     rb-fsevent (0.9.8)
     rb-inotify (0.9.8)
       ffi (>= 0.5.0)