diff --git a/src/machine/usb.go b/src/machine/usb.go
index 7a8c4f0c..313920a7 100644
--- a/src/machine/usb.go
+++ b/src/machine/usb.go
@@ -56,10 +56,6 @@ var (
 var (
 	usbEndpointDescriptors [usb.NumberOfEndpoints]usb.DeviceDescriptor
 
-	udd_ep_control_cache_buffer [256]uint8
-	udd_ep_in_cache_buffer      [7][64]uint8
-	udd_ep_out_cache_buffer     [7][64]uint8
-
 	isEndpointHalt        = false
 	isRemoteWakeUpEnabled = false
 
@@ -67,6 +63,15 @@ var (
 	usbSetInterface  uint8
 )
 
+//go:align 4
+var udd_ep_control_cache_buffer [256]uint8
+
+//go:align 4
+var udd_ep_in_cache_buffer [7][64]uint8
+
+//go:align 4
+var udd_ep_out_cache_buffer [7][64]uint8
+
 var (
 	usbTxHandler    [usb.NumberOfEndpoints]func()
 	usbRxHandler    [usb.NumberOfEndpoints]func([]byte)