diff --git a/Makefile b/Makefile
index 7ced991..72d3974 100644
--- a/Makefile
+++ b/Makefile
@@ -13,7 +13,10 @@ BOARD ?= cynthion
 
 # These should default to the latest hardware revision but can be set on the command line.
 BOARD_REVISION_MAJOR ?= 1
-BOARD_REVISION_MINOR ?= 3
+BOARD_REVISION_MINOR ?= 4
+
+VERSION_MAJOR = 1
+VERSION_MINOR = 0
 
 CROSS=arm-none-eabi-
 
@@ -44,7 +47,9 @@ CFLAGS += \
 			-D USB_MANUFACTURER_STR='"Saturn-V Project"' \
 			-D USB_PRODUCT_STR='$(PRODUCT_STRING)' \
 			-D_BOARD_REVISION_MAJOR_=$(BOARD_REVISION_MAJOR) \
-			-D_BOARD_REVISION_MINOR_=$(BOARD_REVISION_MINOR)
+			-D_BOARD_REVISION_MINOR_=$(BOARD_REVISION_MINOR) \
+			-D VERSION_MAJOR=$(VERSION_MAJOR) \
+			-D VERSION_MINOR=$(VERSION_MINOR)
 
 # Header file search path
 PRJ_PATH = deps
diff --git a/usb.c b/usb.c
index 5e26de4..9518a05 100644
--- a/usb.c
+++ b/usb.c
@@ -16,6 +16,10 @@ char* get_serial_number_string();
 
 USB_ENDPOINTS(1);
 
+#define BCD_ONES(x)     (x % 10)
+#define BCD_TENS(x)     ((x / 10) % 10)
+#define BCDDEVICE(x, y) (BCD_TENS(x)<<12 | BCD_ONES(x)<<8 | BCD_TENS(y)<<4 | BCD_ONES(y))
+
 const USB_DeviceDescriptor device_descriptor = {
 	.bLength = sizeof(USB_DeviceDescriptor),
 	.bDescriptorType = USB_DTYPE_Device,
@@ -28,7 +32,7 @@ const USB_DeviceDescriptor device_descriptor = {
 	.bMaxPacketSize0        = 64,
 	.idVendor               = 0x1d50,
 	.idProduct              = 0x615c,
-	.bcdDevice              = 0x0000,
+	.bcdDevice              = BCDDEVICE(VERSION_MAJOR, VERSION_MINOR),
 
 	.iManufacturer          = 0x01,
 	.iProduct               = 0x02,
@@ -260,4 +264,4 @@ char *get_serial_number_string(void)
 
 	return buf;
 
-}
\ No newline at end of file
+}