diff --git a/samples/subsys/usb/dfu/src/usb_dfu.c b/samples/subsys/usb/dfu/src/usb_dfu.c
index 68f7e5b2cc0..744415ad67a 100644
--- a/samples/subsys/usb/dfu/src/usb_dfu.c
+++ b/samples/subsys/usb/dfu/src/usb_dfu.c
@@ -197,8 +197,8 @@ static const u8_t dfu_mode_usb_description[] = {
 	USB_CONFIGURATION_DESC_SIZE,    /* Descriptor size */
 	USB_CONFIGURATION_DESC,         /* Descriptor type */
 	/* Total length in bytes of data returned */
-	LOW_BYTE(DFU_RUNTIME_CONF_SIZE),
-	HIGH_BYTE(DFU_RUNTIME_CONF_SIZE),
+	LOW_BYTE(DFU_MODE_CONF_SIZE),
+	HIGH_BYTE(DFU_MODE_CONF_SIZE),
 	DFU_NUM_ITF,                    /* Number of interfaces */
 	0x01,                           /* Configuration value */
 	0x00,                           /* Index of the Configuration string */
diff --git a/samples/subsys/usb/dfu/src/usb_dfu.h b/samples/subsys/usb/dfu/src/usb_dfu.h
index b17e5a0fc03..cb11764d301 100644
--- a/samples/subsys/usb/dfu/src/usb_dfu.h
+++ b/samples/subsys/usb/dfu/src/usb_dfu.h
@@ -116,11 +116,11 @@ enum dfu_state {
  * For DFU: CONF + ITF*ALT_SETTINGS + DFU)
  */
 #define DFU_MODE_CONF_SIZE   (USB_CONFIGURATION_DESC_SIZE +    \
-	USB_INTERFACE_DESC_SIZE * DFU_RUNTIME_ALTERNATE_SETTINGS + \
+	USB_INTERFACE_DESC_SIZE * DFU_MODE_ALTERNATE_SETTINGS + \
 	USB_DFU_DESC_SIZE)
 
 #define DFU_RUNTIME_CONF_SIZE   (USB_CONFIGURATION_DESC_SIZE + \
-	USB_INTERFACE_DESC_SIZE * DFU_MODE_ALTERNATE_SETTINGS +    \
+	USB_INTERFACE_DESC_SIZE * DFU_RUNTIME_ALTERNATE_SETTINGS +    \
 	USB_DFU_DESC_SIZE)
 
 /* Alternate settings are used to access additional memory segments.