diff --git a/devicemodel/hw/pci/lpc.c b/devicemodel/hw/pci/lpc.c
index dc50a092b..3cb0da0a4 100644
--- a/devicemodel/hw/pci/lpc.c
+++ b/devicemodel/hw/pci/lpc.c
@@ -31,6 +31,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <stdbool.h>
+#include <sys/errno.h>
 
 #include "vmmapi.h"
 #include "acpi.h"
@@ -214,7 +215,12 @@ lpc_init(struct vmctx *ctx)
 			goto init_failed;
 		}
 
-		if (uart_set_backend(lpc_uart->uart, lpc_uart->opts) != 0) {
+		error = uart_set_backend(lpc_uart->uart, lpc_uart->opts);
+		/*
+		 * Continue to initialize LPC UART device if opts is invalid,
+		 * and the data will be dropped by uart_write in UART DM.
+		 */
+		if (error && error != -EINVAL) {
 			fprintf(stderr, "Unable to initialize backend '%s' "
 			    "for LPC device %s\n", lpc_uart->opts, name);
 			uart_deinit(lpc_uart->uart);
diff --git a/devicemodel/hw/pci/uart.c b/devicemodel/hw/pci/uart.c
index 1376d9480..a8633198f 100644
--- a/devicemodel/hw/pci/uart.c
+++ b/devicemodel/hw/pci/uart.c
@@ -27,6 +27,7 @@
  */
 
 #include <stdio.h>
+#include <sys/errno.h>
 
 #include "pci_core.h"
 #include "uart_core.h"
@@ -82,6 +83,7 @@ static int
 pci_uart_init(struct vmctx *ctx, struct pci_vdev *dev, char *opts)
 {
 	struct uart_vdev *uart;
+	int ret;
 
 	pci_emul_alloc_bar(dev, 0, PCIBAR_IO, UART_IO_BAR_SIZE);
 	pci_lintr_request(dev);
@@ -94,7 +96,8 @@ pci_uart_init(struct vmctx *ctx, struct pci_vdev *dev, char *opts)
 	uart = uart_init(pci_uart_intr_assert, pci_uart_intr_deassert, dev);
 	dev->arg = uart;
 
-	if (uart_set_backend(uart, opts) != 0) {
+	ret = uart_set_backend(uart, opts);
+	if (ret && ret != -EINVAL) {
 		fprintf(stderr, "Unable to initialize backend '%s' for "
 		    "pci uart at %d:%d\n", opts, dev->slot, dev->func);
 		return -1;
diff --git a/devicemodel/hw/uart_core.c b/devicemodel/hw/uart_core.c
index 02dc297a0..b666503fb 100644
--- a/devicemodel/hw/uart_core.c
+++ b/devicemodel/hw/uart_core.c
@@ -36,6 +36,7 @@
 #include <stdbool.h>
 #include <string.h>
 #include <pthread.h>
+#include <sys/errno.h>
 
 #include "types.h"
 #include "mevent.h"
@@ -679,7 +680,7 @@ uart_set_backend(struct uart_vdev *uart, const char *opts)
 	retval = -1;
 
 	if (opts == NULL)
-		return 0;
+		return -EINVAL;
 
 	if (strcmp("stdio", opts) == 0) {
 		if (!stdio_in_use) {
@@ -692,6 +693,9 @@ uart_set_backend(struct uart_vdev *uart, const char *opts)
 		retval = 0;
 	}
 
+	if (retval)
+		return -EINVAL;
+
 	/* Make the backend file descriptor non-blocking */
 	if (retval == 0)
 		retval = fcntl(uart->tty.fd, F_SETFL, O_NONBLOCK);