diff --git a/src/midi_device.rs b/src/midi_device.rs
index 92df3d6..66c2301 100644
--- a/src/midi_device.rs
+++ b/src/midi_device.rs
@@ -4,7 +4,7 @@ use crate::data::usb::constants::*;
 use crate::data::usb_midi::usb_midi_event_packet::{UsbMidiEventPacket, MidiPacketParsingError};
 
 const MIDI_IN_SIZE: u8 = 0x06;
-const MIDI_OUT_SIZE: u8 = 0x07;
+const MIDI_OUT_SIZE: u8 = 0x09;
 
 pub const MIDI_PACKET_SIZE: usize = 4;
 pub const MAX_PACKET_SIZE: usize = 64;
@@ -104,7 +104,7 @@ impl<B: UsbBus> UsbClass<B> for MidiClass<'_, B> {
         let midi_streaming_start_byte = writer.position();
         let midi_streaming_total_length =
             7 + self.n_in_jacks as usize * MIDI_IN_SIZE as usize + self.n_out_jacks as usize * MIDI_OUT_SIZE as usize
-            + 7 + (4+self.n_in_jacks as usize) + 7 + (4+self.n_out_jacks as usize);
+            + 9 + (4+self.n_in_jacks as usize) + 9 + (4+self.n_out_jacks as usize);
 
         //Streaming extra info
         writer.write( // len = 7
@@ -137,6 +137,7 @@ impl<B: UsbBus> UsbClass<B> for MidiClass<'_, B> {
                     EMBEDDED,
                     self.out_jack_id(i), //id
                     0x00, // no pins
+                    0x00, 0x00, // windows wants these two bytes, no idea why. they don't belong here.
                     0x00
                 ]
             )?;
@@ -148,7 +149,7 @@ impl<B: UsbBus> UsbClass<B> for MidiClass<'_, B> {
             0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 // jack mappings. must be filled in and cropped.
         ];
 
-        writer.endpoint(&self.standard_bulkout)?; // len = 7
+        writer.endpoint(&self.standard_bulkout)?; // len = 9
 
         endpoint_data[1] = self.n_in_jacks;
         for i in 0..self.n_in_jacks {
@@ -159,7 +160,7 @@ impl<B: UsbBus> UsbClass<B> for MidiClass<'_, B> {
             &endpoint_data[0..2+self.n_in_jacks as usize]
         )?;
 
-        writer.endpoint(&self.standard_bulkin)?; // len = 7
+        writer.endpoint(&self.standard_bulkin)?; // len = 9
         endpoint_data[1] = self.n_out_jacks;
         for i in 0..self.n_out_jacks {
             endpoint_data[2 + i as usize] = self.out_jack_id(i);