diff --git a/Gemfile.lock b/Gemfile.lock
index a6ffceb..45b87cd 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -25,7 +25,8 @@ GEM
     rake-compiler (1.3.1)
       rake
     rake-compiler-dock (1.11.0)
-    rb_sys (0.9.124)
+    rb_sys (0.9.125)
+      json (>= 2)
       rake-compiler-dock (= 1.11.0)
     regexp_parser (2.11.3)
     rspec (3.13.2)