diff --git a/Gemfile.lock b/Gemfile.lock
index 1b854b57..99cb3f8d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -132,7 +132,7 @@ GEM
       rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
-    json (2.1.0)
+    json (2.3.1)
     letsencrypt-rails-heroku (1.2.0)
       acme-client (~> 0.4.0)
       platform-api