diff --git a/boot/zephyr/serial_adapter.c b/boot/zephyr/serial_adapter.c
index 5031091..e5ebfdb 100644
--- a/boot/zephyr/serial_adapter.c
+++ b/boot/zephyr/serial_adapter.c
@@ -20,6 +20,7 @@
 #include <string.h>
 #include <zephyr.h>
 #include "bootutil/bootutil_log.h"
+#include <usb/usb_device.h>
 
 #ifdef CONFIG_UART_CONSOLE
 #error Zephyr UART console must been disabled if serial_adapter module is used.
@@ -194,6 +195,13 @@
 	uart_dev = device_get_binding(CONFIG_RECOVERY_UART_DEV_NAME);
 #elif CONFIG_BOOT_SERIAL_CDC_ACM
 	uart_dev = device_get_binding(CONFIG_USB_CDC_ACM_DEVICE_NAME "_0");
+	if (uart_dev) {
+		int rc;
+		rc = usb_enable(NULL);
+		if (rc) {
+			return (-1);
+		}
+	}
 #endif
 	u8_t c;