diff --git a/lib/childprocess/windows/lib.rb b/lib/childprocess/windows/lib.rb
index d275f3b..fd7f478 100644
--- a/lib/childprocess/windows/lib.rb
+++ b/lib/childprocess/windows/lib.rb
@@ -55,9 +55,9 @@ module Lib
       # );
       #
 
-      attach_function :create_process, :CreateProcessA, [
-        :pointer,
+      attach_function :create_process, :CreateProcessW, [
         :pointer,
+        :buffer_inout,
         :pointer,
         :pointer,
         :bool,
diff --git a/lib/childprocess/windows/process_builder.rb b/lib/childprocess/windows/process_builder.rb
index 1b30b0a..1e849d7 100644
--- a/lib/childprocess/windows/process_builder.rb
+++ b/lib/childprocess/windows/process_builder.rb
@@ -39,9 +39,14 @@ def start
 
       private
 
+      def to_wide_string(str)
+        newstr = str + "\0".encode(str.encoding)
+        newstr.encode!('UTF-16LE')
+      end
+      
       def create_command_pointer
-        string = @args.map { |arg| quote_if_necessary(arg.to_s) }.join ' '
-        @cmd_ptr = FFI::MemoryPointer.from_string string
+        string = @args.map { |arg| quote_if_necessary(arg.to_s) }.join(' ')
+        @cmd_ptr = to_wide_string(string)
       end
 
       def create_environment_pointer
@@ -59,15 +64,12 @@ def create_environment_pointer
           strings << "#{key}=#{val}\0"
         end
 
-        strings << "\0" # terminate the env block
-        env_str = strings.join
-
-        @env_ptr = FFI::MemoryPointer.new(:long, env_str.bytesize)
-        @env_ptr.put_bytes 0, env_str, 0, env_str.bytesize
+        env_str = to_wide_string(strings.join)
+        @env_ptr = FFI::MemoryPointer.from_string(env_str)
       end
 
       def create_cwd_pointer
-        @cwd_ptr = FFI::MemoryPointer.from_string(@cwd || Dir.pwd)
+        @cwd_ptr = FFI::MemoryPointer.from_string(to_wide_string(@cwd || Dir.pwd))
       end
 
       def create_process
@@ -98,6 +100,7 @@ def process_info
       end
 
       def setup_flags
+        @flags |= CREATE_UNICODE_ENVIRONMENT
         @flags |= DETACHED_PROCESS if @detach
         @flags |= CREATE_BREAKAWAY_FROM_JOB if @leader
       end
diff --git a/spec/childprocess_spec.rb b/spec/childprocess_spec.rb
index b382122..117ed54 100644
--- a/spec/childprocess_spec.rb
+++ b/spec/childprocess_spec.rb
@@ -107,6 +107,23 @@
       expect(child_env['CHILD_ONLY']).to eql '1'
     end
   end
+  
+  it 'allows unicode characters in the environment' do
+    # This test does not work on Windows for Ruby < 2.3 because ENV values will not be properly decoded
+    # This was fixed in Ruby 2.3 here: https://github.com/ruby/ruby/commit/5e3467c4414df815b3b00d2b0372026b069e7f7d
+    # TODO: Write an alternate test that does not rely on the Ruby ENV hash
+    skip 'Test does not work on Windows for Ruby < 2.3' if Gem.win_platform? && RUBY_VERSION =~ /^1\.|^2\.[0-2]/
+    Tempfile.open("env-spec") do |file|
+      process = write_env(file.path)
+      process.environment['FOO'] = 'baör'
+      process.start
+      process.wait
+      
+      child_env = eval rewind_and_read(file)
+      
+      expect(child_env['FOO'].force_encoding('UTF-8')).to eql 'baör'
+    end
+  end
 
   it "inherits the parent's env vars also when some are overridden" do
     Tempfile.open("env-spec") do |file|