diff --git a/Gemfile b/Gemfile
index 64ea972..b05d248 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,12 +1,11 @@
 # frozen_string_literal: true
-
 source 'https://rubygems.org'
 
 gem 'rake', '~> 13.0', '>= 13.0.6', groups: %i[development test]
 gem 'rspec', '~> 3.11', '>= 3.11.0', groups: %i[test]
-gem 'rubocop', '~> 1.25', '>=  1.25.1', groups: %i[development test]
+gem 'rubocop', '~> 1.10', '>= 1.10.0', groups: %i[development test], require: false
 
-gem 'alsa-rawmidi', '~> 0.3', '>= 0.3.1', require: false # linux
-gem 'ffi-coremidi', '~> 0.5', '>= 0.5.0', require: false # osx
-gem 'midi-jruby', '~> 0.1', '>= 0.1.4', require: false # jruby
+gem 'alsa-rawmidi', '~> 0.4', '>= 0.4.0', require: false # linux
+gem 'ffi-coremidi', '~> 0.5', '>= 0.5.1', require: false # osx
+gem 'midi-jruby', '~> 0.2', '>= 0.2.0', require: false # jruby
 gem 'midi-winmm', '~> 0.1', '>= 0.1.10', require: false # windows
diff --git a/README.md b/README.md
index 660c9ee..40432c8 100644
--- a/README.md
+++ b/README.md
@@ -14,8 +14,6 @@ Also see [MicroMIDI](http://github.com/arirusso/micromidi) which builds a full M
 
 ### Requirements
 
-Using Ruby 1.9.2 or JRuby 1.6.1 (or newer) is strongly recommended.  JRuby should be run in 1.9 mode where applicable
-
 UniMIDI uses one of the following libraries, depending on which platform you're using it on.  The necessary library should install automatically with the unimidi gem.
 
 Platform
@@ -57,7 +55,7 @@ UniMIDI includes a set of tests which assume that an output is connected to an i
 
 The tests can be run using
 
-`rake test`
+`rake spec`
 
 See below for additional notes on testing with JRuby
 
@@ -69,7 +67,6 @@ See below for additional notes on testing with JRuby
 
 ##### JRuby
 
-* You must be in 1.9 mode.  This is normally accomplished by passing --1.9 to JRuby at the command line.  For testing in 1.9 mode, use `jruby --1.9 -S rake test`
 * javax.sound has some documented issues with SysEx messages in some versions OSX Snow Leopard which do affect this library.
 
 ##### Linux
diff --git a/lib/unimidi.rb b/lib/unimidi.rb
index d6b419e..f35b26a 100644
--- a/lib/unimidi.rb
+++ b/lib/unimidi.rb
@@ -20,7 +20,7 @@
 require 'unimidi/output'
 
 module UniMIDI
-  VERSION = '0.5.0'
+  VERSION = '0.5.1'
 
   Platform.bootstrap
 end
diff --git a/lib/unimidi/adapter/alsa-rawmidi.rb b/lib/unimidi/adapter/alsa-rawmidi.rb
index fd80034..0fc9653 100644
--- a/lib/unimidi/adapter/alsa-rawmidi.rb
+++ b/lib/unimidi/adapter/alsa-rawmidi.rb
@@ -1,5 +1,4 @@
 # frozen_string_literal: true
-
 require 'alsa-rawmidi'
 
 module UniMIDI
diff --git a/spec/integration/helper.rb b/spec/integration/helper.rb
index 400630e..07b941c 100644
--- a/spec/integration/helper.rb
+++ b/spec/integration/helper.rb
@@ -9,7 +9,7 @@ module Integration
     module_function
 
     def sysex_ok?
-      ENV['_system_name'] != 'OSX' || !RUBY_PLATFORM.include?('java')
+      !RUBY_PLATFORM.include?('java') || RbConfig::CONFIG["host_os"] != 'darwin'
     end
 
     def devices
diff --git a/spec/integration/input_spec.rb b/spec/integration/input_spec.rb
index 3073b2e..e7701df 100644
--- a/spec/integration/input_spec.rb
+++ b/spec/integration/input_spec.rb
@@ -8,7 +8,7 @@
     let(:output) { SpecHelper::Integration.devices[:output].open }
     let(:messages) { SpecHelper::Integration.numeric_messages }
     before do
-      sleep 0.1
+      sleep 0.3
       input.buffer.clear
     end
 
@@ -24,7 +24,7 @@
         p "sending: #{message}"
         output.puts(message)
         sent_bytes += message
-        sleep 0.1
+        sleep 0.3
         buffer = input.buffer.map { |m| m[:data] }.flatten
         p "received: #{buffer}"
         expect(buffer).to eq(sent_bytes)
diff --git a/spec/integration/io_spec.rb b/spec/integration/io_spec.rb
index 8a62e5c..95ff435 100644
--- a/spec/integration/io_spec.rb
+++ b/spec/integration/io_spec.rb
@@ -6,7 +6,10 @@
   # these tests assume that TestOutput is connected to TestInput
   let(:input) { SpecHelper::Integration.devices[:input].open }
   let(:output) { SpecHelper::Integration.devices[:output].open }
-
+  before do
+    sleep 0.3
+    input.buffer.clear
+  end
   after do
     input.close
     output.close
@@ -23,7 +26,7 @@
           p "sending: #{message}"
 
           output.puts(message)
-          sleep(0.1)
+          sleep 0.3
           received = input.gets.map { |m| m[:data] }.flatten
 
           p "received: #{received}"
@@ -46,7 +49,7 @@
           p "sending: #{message}"
 
           output.puts(message)
-          sleep(0.1)
+          sleep 0.3
           received = input.gets_bytestr.map { |m| m[:data] }.flatten.join
           p "received: #{received}"
 
@@ -69,7 +72,7 @@
           p "sending: #{message.inspect}"
 
           output.puts(message)
-          sleep(0.1)
+          sleep 0.3
           received = input.gets.map { |m| m[:data] }.flatten
 
           p "received: #{received}"