diff --git a/build/jam/HaikuImage b/build/jam/HaikuImage
index 16a559484a..50387fd745 100644
--- a/build/jam/HaikuImage
+++ b/build/jam/HaikuImage
@@ -145,7 +145,7 @@ SYSTEM_ADD_ONS_DRIVERS_GRAPHICS = $(X86_ONLY)radeon $(X86_ONLY)nvidia
 	$(X86_ONLY)s3 $(X86_ONLY)vesa #$(X86_ONLY)via #$(X86_ONLY)vmware
 	$(X86_ONLY)ati
 ;
-SYSTEM_ADD_ONS_DRIVERS_MIDI = emuxki ;
+SYSTEM_ADD_ONS_DRIVERS_MIDI = emuxki usb_midi ;
 SYSTEM_ADD_ONS_DRIVERS_NET = $(X86_ONLY)3com $(X86_ONLY)broadcom440x
 	$(X86_ONLY)broadcom570x etherpci $(X86_ONLY)ipro1000
 	pegasus $(X86_ONLY)rtl8139 rtl8169 $(X86_ONLY)rtl81xx sis900
diff --git a/src/add-ons/kernel/drivers/midi/usb_midi/usb_midi.c b/src/add-ons/kernel/drivers/midi/usb_midi/usb_midi.c
index 122283c18f..4e0dba5a42 100644
--- a/src/add-ons/kernel/drivers/midi/usb_midi/usb_midi.c
+++ b/src/add-ons/kernel/drivers/midi/usb_midi/usb_midi.c
@@ -146,8 +146,8 @@ interpret_midi_buffer(my_device_info *my_dev)
 */
 
 static void 
-midi_usb_callback(void *cookie, uint32 status, 
-	void *data, uint32 actual_len)
+midi_usb_callback(void *cookie, status_t status, 
+	void *data, size_t actual_len)
 {
 	status_t st;
 	my_device_info *my_dev = cookie;