diff --git a/sasbook/Gemfile.lock b/sasbook/Gemfile.lock
index 5b38263..fc4f47d 100644
--- a/sasbook/Gemfile.lock
+++ b/sasbook/Gemfile.lock
@@ -58,7 +58,7 @@ GEM
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
     public_suffix (4.0.1)
-    rack (1.6.11)
+    rack (1.6.12)
     rack-protection (1.5.5)
       rack
     rack-test (1.1.0)