diff --git a/clojure-book/Gemfile.lock b/clojure-book/Gemfile.lock
index 61c32a1..1df3ee2 100644
--- a/clojure-book/Gemfile.lock
+++ b/clojure-book/Gemfile.lock
@@ -69,7 +69,7 @@ GEM
       ffi (>= 0.5.0)
     redcarpet (3.3.1)
     rouge (1.9.0)
-    rubyzip (1.1.7)
+    rubyzip (2.3.0)
     sass (3.4.14)
     sass-globbing (1.1.1)
       sass (>= 3.1)