diff --git a/Gemfile b/Gemfile
index 64c5aa1..88e2ebf 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,11 +11,9 @@ gem "rubocop-rake", ">= 0.6.0"
 gem "rubocop-rspec", ">= 2.27.1"
 gem "standard", ">= 1.35.1"
 
-if RUBY_DESCRIPTION.start_with?("jruby")
-  gem "gson", ">= 0.6", require: false
-else
-  gem "oj", "~> 3.0", require: false
-  gem "yajl-ruby", "~> 1.3", require: false
-end
+gem "gson", ">= 0.6", platforms: [:jruby], require: false
+gem "jrjackson", ">= 0.4.18", platforms: [:jruby], require: false
+gem "oj", "~> 3.0", platforms: [:ruby], require: false
+gem "yajl-ruby", "~> 1.3", platforms: [:ruby], require: false
 
 gemspec