diff --git a/Gemfile.lock b/Gemfile.lock
index ba583fc5..ecc39212 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -63,7 +63,7 @@ GEM
     hashery (2.1.2)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
-    json (2.1.0)
+    json (2.3.1)
     kindlegen (3.0.3)
       rake
       rubyzip