diff --git a/oauth2/web/Gemfile.lock b/oauth2/web/Gemfile.lock
index b5bfb5b..b49913b 100644
--- a/oauth2/web/Gemfile.lock
+++ b/oauth2/web/Gemfile.lock
@@ -13,7 +13,7 @@ GEM
       httpauth (~> 0.1)
       multi_json (~> 1.0)
       rack (~> 1.4)
-    rack (1.4.1)
+    rack (1.6.12)
     rack-protection (1.2.0)
       rack
     rack-test (0.6.1)