diff --git a/include/usb/usb_common.h b/include/usb/usb_common.h
index e723b2bd41a..8eaf4c325d2 100644
--- a/include/usb/usb_common.h
+++ b/include/usb/usb_common.h
@@ -103,7 +103,6 @@
 #define DFU_CLASS			0xFE
 
 /* Sub-classes */
-#define ACM_SUBCLASS			0x02
 #define CDC_NCM_SUBCLASS		0x0d
 #define BOOT_INTERFACE_SUBCLASS		0x01
 #define SCSI_TRANSPARENT_SUBCLASS	0x06