diff --git a/Gemfile.lock b/Gemfile.lock
index 1db3332..b1a7376 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -29,7 +29,7 @@ GEM
       multi_xml (>= 0.5.2)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
-    json (2.1.0)
+    json (2.3.1)
     minitest (5.11.3)
     multi_xml (0.6.0)
     oj (3.5.0)