diff --git a/Gemfile b/Gemfile
index a310188f..8355c1b9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -76,6 +76,7 @@ group :jekyll_optional_dependencies do
     gem "classifier-reborn", "~> 2.1.0"
     gem "liquid-c", "~> 3.0"
     gem "pygments.rb", "~> 0.6.0"
+    gem "yajl-ruby", git: "https://github.com/parkr/yajl-ruby", branch: "1.2.x-unify-fixnum-to-integer"
     gem "rdiscount", "~> 2.0"
     gem "redcarpet", "~> 3.2", ">= 3.2.3"
   end