diff --git a/hw/char/serial.c b/hw/char/serial.c
index f11f2cdbf3..1d350a851b 100644
--- a/hw/char/serial.c
+++ b/hw/char/serial.c
@@ -1093,6 +1093,7 @@ SerialMM *serial_mm_init(MemoryRegion *address_space,
     qdev_prop_set_uint32(DEVICE(s), "baudbase", baudbase);
     qdev_prop_set_chr(DEVICE(s), "chardev", chr);
     qdev_set_legacy_instance_id(DEVICE(s), base, 2);
+    qdev_prop_set_uint8(DEVICE(self), "endianness", end);
 
     qdev_init_nofail(DEVICE(smm));
 
@@ -1118,6 +1119,7 @@ static Property serial_mm_properties[] = {
      * previous one.
      */
     DEFINE_PROP_UINT8("regshift", SerialMM, regshift, 0),
+    DEFINE_PROP_UINT8("endianness", SerialMM, endianness, DEVICE_NATIVE_ENDIAN),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/char/serial.h b/include/hw/char/serial.h
index eaeda62698..d586924937 100644
--- a/include/hw/char/serial.h
+++ b/include/hw/char/serial.h
@@ -85,6 +85,7 @@ typedef struct SerialMM {
     SerialState serial;
 
     uint8_t regshift;
+    uint8_t endianness;
 } SerialMM;
 
 extern const VMStateDescription vmstate_serial;