diff --git a/lib/open3.gemspec b/lib/open3.gemspec
index ad9485adc7..89c2cbe564 100644
--- a/lib/open3.gemspec
+++ b/lib/open3.gemspec
@@ -1,10 +1,8 @@
 # frozen_string_literal: true
 
 name = File.basename(__FILE__, ".gemspec")
-version = ["lib", Array.new(name.count("-"), "..").join("/")].find do |dir|
-  break File.foreach(File.join(__dir__, dir, "#{name.tr('-', '/')}.rb")) do |line|
-    /^\s*VERSION\s*=\s*"(.*)"/ =~ line and break $1
-  end rescue nil
+version = File.foreach(File.join(__dir__, "lib/open3/version.rb")) do |line|
+  /^\s*VERSION\s*=\s*"(.*)"/ =~ line and break $1
 end
 
 Gem::Specification.new do |spec|
diff --git a/lib/open3.rb b/lib/open3.rb
index c574696bb1..2f035e3bcd 100644
--- a/lib/open3.rb
+++ b/lib/open3.rb
@@ -29,9 +29,14 @@
 # - Open3.pipeline : run a pipeline and wait for its completion
 #
 
-module Open3
-  VERSION = "0.1.1"
+require 'open3/version'
 
+if RUBY_ENGINE == 'jruby' && JRuby::Util::ON_WINDOWS
+  require_relative 'open3/jruby_windows'
+  return
+end
+
+module Open3
   # Open stdin, stdout, and stderr streams and start external executable.
   # In addition, a thread to wait for the started process is created.
   # The thread has a pid method and a thread variable :pid which is the pid of
diff --git a/lib/open3/jruby_windows.rb b/lib/open3/jruby_windows.rb
new file mode 100644
index 0000000000..24b9a1ba7e
--- /dev/null
+++ b/lib/open3/jruby_windows.rb
@@ -0,0 +1,118 @@
+#
+# Custom implementation of Open3.popen{3,2,2e} that uses java.lang.ProcessBuilder rather than pipes and spawns.
+#
+
+require 'jruby' # need access to runtime for RubyStatus construction
+
+module Open3
+
+  java_import java.lang.ProcessBuilder
+  java_import org.jruby.RubyProcess
+  java_import org.jruby.util.ShellLauncher
+
+  def popen3(*cmd, &block)
+    if cmd.size > 0 && Hash === cmd[-1]
+      opts = cmd.pop
+    else
+      opts = {}
+    end
+    processbuilder_run(cmd, opts, io: IO_3, &block)
+  end
+  module_function :popen3
+
+  IO_3 = proc do |process|
+    [process.getOutputStream.to_io, process.getInputStream.to_io, process.getErrorStream.to_io]
+  end
+
+  BUILD_2 = proc do |builder|
+    builder.redirectError(ProcessBuilder::Redirect::INHERIT)
+  end
+
+  IO_2 = proc do |process|
+    [process.getOutputStream.to_io, process.getInputStream.to_io]
+  end
+
+  def popen2(*cmd, &block)
+    if cmd.size > 0 && Hash === cmd[-1]
+      opts = cmd.pop
+    else
+      opts = {}
+    end
+    processbuilder_run(cmd, opts, build: BUILD_2, io: IO_2, &block)
+  end
+  module_function :popen2
+
+  BUILD_2E = proc do |builder|
+    builder.redirectErrorStream(true)
+  end
+
+  def popen2e(*cmd, &block)
+    if cmd.size > 0 && Hash === cmd[-1]
+      opts = cmd.pop
+    else
+      opts = {}
+    end
+    processbuilder_run(cmd, opts, build: BUILD_2E, io: IO_2, &block)
+  end
+  module_function :popen2e
+
+  def processbuilder_run(cmd, opts, build: nil, io:)
+    if Hash === cmd[0]
+      env = cmd.shift;
+    else
+      env = {}
+    end
+
+    if cmd.size == 1 && (cmd[0] =~ / / || ShellLauncher.shouldUseShell(cmd[0]))
+      cmd = [RbConfig::CONFIG['SHELL'], JRuby::Util::ON_WINDOWS ? '/c' : '-c', cmd[0]]
+    end
+
+    builder = ProcessBuilder.new(cmd.to_java(:string))
+
+    builder.directory(java.io.File.new(opts[:chdir] || Dir.pwd))
+
+    environment = builder.environment
+    env.each { |k, v| v.nil? ? environment.remove(k) : environment.put(k, v) }
+
+    build.call(builder) if build
+
+    process = builder.start
+
+    pid = org.jruby.util.ShellLauncher.getPidFromProcess(process)
+
+    parent_io = io.call(process)
+
+    parent_io.each {|i| i.sync = true}
+
+    wait_thr = DetachThread.new(pid) { RubyProcess::RubyStatus.newProcessStatus(JRuby.runtime, process.waitFor << 8, pid) }
+
+    result = [*parent_io, wait_thr]
+
+    if defined? yield
+      begin
+        return yield(*result)
+      ensure
+        parent_io.each(&:close)
+        wait_thr.join
+      end
+    end
+
+    result
+  end
+  module_function :processbuilder_run
+  class << self
+    private :processbuilder_run
+  end
+
+  class DetachThread < Thread
+    attr_reader :pid
+
+    def initialize(pid)
+      super
+
+      @pid = pid
+      self[:pid] = pid
+    end
+  end
+
+end
diff --git a/lib/open3/version.rb b/lib/open3/version.rb
new file mode 100644
index 0000000000..5a8e84b4ae
--- /dev/null
+++ b/lib/open3/version.rb
@@ -0,0 +1,3 @@
+module Open3
+  VERSION = "0.1.1"
+end