diff --git a/.ruby-version b/.ruby-version
new file mode 100644
index 0000000..3361fb0
--- /dev/null
+++ b/.ruby-version
@@ -0,0 +1 @@
+jruby-1.7.24
diff --git a/lib/jna-platform.jar b/lib/jna-platform.jar
new file mode 100644
index 0000000..f3a9fd2
Binary files /dev/null and b/lib/jna-platform.jar differ
diff --git a/lib/jna.jar b/lib/jna.jar
new file mode 100644
index 0000000..a943670
Binary files /dev/null and b/lib/jna.jar differ
diff --git a/lib/systemu.rb b/lib/systemu.rb
index 5f7745a..595f6b9 100644
--- a/lib/systemu.rb
+++ b/lib/systemu.rb
@@ -291,9 +291,26 @@ def systemu
         StreamReader.new(stream)
       end
 
-      field = process.get_class.get_declared_field("pid")
-      field.set_accessible(true)
-      pid = field.get(process)
+      pid = nil
+      if process.get_class.get_name == "java.lang.UNIXProcess"
+        field = process.get_class.get_declared_field("pid")
+        field.set_accessible(true)
+        pid = field.get_int(process)
+      else
+        # Import java classes
+        java_import com.sun.jna.Pointer
+        java_import com.sun.jna.platform.win32.Kernel32
+        java_import com.sun.jna.platform.win32.WinNT
+
+        field = process.get_class.get_declared_field("handle")
+        field.set_accessible(true)
+        handl = field.get_long(process)
+
+        krnl = Kernel32.INSTANCE
+        handle = WinNT::HANDLE.new
+        handle.setPointer(Pointer.createConstant(handl))
+        pid = krnl.GetProcessId(handle)
+      end
       thread = new_thread pid, @block if @block
       exit_code = process.wait_for
       [
diff --git a/systemu.gemspec b/systemu.gemspec
index bfe834c..b4b869e 100644
--- a/systemu.gemspec
+++ b/systemu.gemspec
@@ -1,40 +1,28 @@
 ## systemu.gemspec
 #
 
+$:.push File.expand_path("../lib", __FILE__)
+
 Gem::Specification::new do |spec|
   spec.name = "systemu"
-  spec.version = "2.6.4"
+  spec.version = "2.6.6"
   spec.platform = Gem::Platform::RUBY
   spec.summary = "systemu"
   spec.description = "universal capture of stdout and stderr and handling of child process pid for windows, *nix, etc."
   spec.license = "Ruby"
 
-  spec.files =
-["LICENSE",
- "README",
- "README.erb",
- "Rakefile",
- "lib",
- "lib/systemu.rb",
- "samples",
- "samples/a.rb",
- "samples/b.rb",
- "samples/c.rb",
- "samples/d.rb",
- "samples/e.rb",
- "samples/f.rb",
- "systemu.gemspec",
- "test",
- "test/systemu_test.rb",
- "test/testing.rb"]
+  spec.files = `git ls-files`.split("\n").
+    select { |f| f =~ /^(lib)/ ||
+                 f =~ /^History|LICENSE|README|Rakefile|Mavenfile|pom.xml/i } +
+    Dir.glob('lib/**/*.jar') # 'lib/jopenssl.jar' and potentially BC jars
 
   spec.executables = []
-  
+
   spec.require_path = "lib"
 
   spec.test_files = nil
 
-  
+
 
   spec.extensions.push(*[])