diff --git a/hermann.gemspec b/hermann.gemspec
index b8c97ad..492ee30 100644
--- a/hermann.gemspec
+++ b/hermann.gemspec
@@ -24,14 +24,13 @@ Gem::Specification.new do |s|
   s.rubygems_version = '2.2.2'
   s.specification_version = 3 if s.respond_to?(:specification_version)
 
-  s.add_dependency 'concurrent-ruby', '~> 0.7.0'
-  s.add_dependency 'thread_safe', '~> 0.3.4'
-
   if RUBY_PLATFORM == "java"
     # IMPORTANT: make sure that jar-dependencies is only a development
     # dependency of your gem. if it is a runtime dependencies the require_jars
     # file will be overwritten during installation.
     s.add_dependency 'jar-dependencies', '~>0.1.9'
+    s.add_dependency 'concurrent-ruby', '~> 0.7.0'
+    s.add_dependency 'thread_safe', '~> 0.3.4'
     s.requirements << "jar org.apache.kafka:kafka_2.10, ~>0.8.1.1, ['junit:junit']"
     # use log4j-1.2.16+ to as 1.2.15 declares deps which are not in maven central and causes the dep resolution to fail
     s.requirements << "jar log4j:log4j, ~>1.2.16"
diff --git a/lib/hermann/provider/java_producer.rb b/lib/hermann/provider/java_producer.rb
index de5c9d3..148aee0 100644
--- a/lib/hermann/provider/java_producer.rb
+++ b/lib/hermann/provider/java_producer.rb
@@ -1,8 +1,11 @@
 require 'hermann'
-require 'concurrent'
 require 'json'
 require 'hermann/errors'
 
+if Hermann.jruby?
+  require 'concurrent'
+end
+
 module Hermann
   module Provider
     # This class simulates the kafka producer class within a java environment.
diff --git a/spec/integration/producer_spec.rb b/spec/integration/producer_spec.rb
index 20d7067..93da1d1 100644
--- a/spec/integration/producer_spec.rb
+++ b/spec/integration/producer_spec.rb
@@ -3,7 +3,10 @@ require 'spec_helper'
 require 'hermann/producer'
 require 'hermann/consumer'
 require 'hermann/discovery/zookeeper'
-require 'concurrent'
+
+if Hermann.jruby?
+  require 'concurrent'
+end
 
 require 'protobuf'
 require_relative '../fixtures/testevent.pb'
@@ -14,7 +17,7 @@ describe 'producer' do
   let(:timeout) { 10 }
   let(:message)   { 'msg' }
   let(:consumer) do
-    Hermann::Consumer.new(topic, "rspec-group", zookeepers)
+    Hermann::Consumer.new(topic, {:group_id => "rspec-group", :zookeepers => zookeepers})
   end
   let(:consumer_promise) do
     Concurrent::Promise.execute do