diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c
index 3651e0c0d4..08c654e901 100644
--- a/xen/drivers/char/ns16550.c
+++ b/xen/drivers/char/ns16550.c
@@ -271,6 +271,14 @@ static int ns16550_getc(struct serial_port *port, char *pc)
 static void pci_serial_early_init(struct ns16550 *uart)
 {
 #ifdef NS16550_PCI
+    if ( uart->bar && uart->io_base >= 0x10000 )
+    {
+        pci_conf_write16(PCI_SBDF(0, uart->ps_bdf[0], uart->ps_bdf[1],
+                                  uart->ps_bdf[2]),
+                         PCI_COMMAND, PCI_COMMAND_MEMORY);
+        return;
+    }
+
     if ( !uart->ps_bdf_enable || uart->io_base >= 0x10000 )
         return;