diff --git a/drivers/cyw43/cywbt.c b/drivers/cyw43/cywbt.c
index 79318f4483ba..2d88feac37fc 100644
--- a/drivers/cyw43/cywbt.c
+++ b/drivers/cyw43/cywbt.c
@@ -53,12 +53,12 @@ STATIC void cywbt_wait_cts_low(void) {
 }
 
 STATIC int cywbt_hci_cmd_raw(size_t len, uint8_t *buf) {
-    uart_tx_strn(&mp_bluetooth_hci_uart_obj, (void*)buf, len);
+    uart_tx_strn(mp_bluetooth_hci_uart_obj, (void*)buf, len);
     for (int i = 0; i < 6; ++i) {
-        while (!uart_rx_any(&mp_bluetooth_hci_uart_obj)) {
+        while (!uart_rx_any(mp_bluetooth_hci_uart_obj)) {
             MICROPY_EVENT_POLL_HOOK
         }
-        buf[i] = uart_rx_char(&mp_bluetooth_hci_uart_obj);
+        buf[i] = uart_rx_char(mp_bluetooth_hci_uart_obj);
     }
 
     // expect a comand complete event (event 0x0e)
@@ -75,10 +75,10 @@ STATIC int cywbt_hci_cmd_raw(size_t len, uint8_t *buf) {
 
     int sz = buf[2] - 3;
     for (int i = 0; i < sz; ++i) {
-        while (!uart_rx_any(&mp_bluetooth_hci_uart_obj)) {
+        while (!uart_rx_any(mp_bluetooth_hci_uart_obj)) {
             MICROPY_EVENT_POLL_HOOK
         }
-        buf[i] = uart_rx_char(&mp_bluetooth_hci_uart_obj);
+        buf[i] = uart_rx_char(mp_bluetooth_hci_uart_obj);
     }
 
     return 0;
diff --git a/extmod/modbluetooth_hci.h b/extmod/modbluetooth_hci.h
index d6b432d22471..6b6451d9b10a 100644
--- a/extmod/modbluetooth_hci.h
+++ b/extmod/modbluetooth_hci.h
@@ -45,7 +45,7 @@ int mp_bluetooth_hci_controller_wakeup(void);
 // These are used by the stack bindings (e.g. nimble/hal_uart.c)
 // as well as potentially the driver (e.g. cywbt.c).
 extern uint8_t mp_bluetooth_hci_cmd_buf[4 + 256];
-extern pyb_uart_obj_t mp_bluetooth_hci_uart_obj;
+extern pyb_uart_obj_t *mp_bluetooth_hci_uart_obj;
 
 int mp_bluetooth_hci_uart_init(uint32_t port);
 int mp_bluetooth_hci_uart_activate(void);
diff --git a/ports/stm32/modbluetooth_hci.c b/ports/stm32/modbluetooth_hci.c
index 4e016eae8451..dc59ca834993 100644
--- a/ports/stm32/modbluetooth_hci.c
+++ b/ports/stm32/modbluetooth_hci.c
@@ -134,7 +134,7 @@ int mp_bluetooth_hci_uart_readchar(void) {
 #include "pendsv.h"
 #include "uart.h"
 
-pyb_uart_obj_t mp_bluetooth_hci_uart_obj;
+pyb_uart_obj_t *mp_bluetooth_hci_uart_obj;
 
 static uint8_t hci_uart_rxbuf[512];
 
@@ -147,25 +147,28 @@ MP_DEFINE_CONST_FUN_OBJ_1(mp_uart_interrupt_obj, mp_uart_interrupt);
 
 int mp_bluetooth_hci_uart_init(uint32_t port) {
     // bits (8), stop (1), parity (none) and flow (rts/cts) are assumed to match MYNEWT_VAL_BLE_HCI_UART_ constants in syscfg.h.
-    mp_bluetooth_hci_uart_obj.base.type = &pyb_uart_type;
-    mp_bluetooth_hci_uart_obj.uart_id = port;
-    mp_bluetooth_hci_uart_obj.is_static = true;
-    mp_bluetooth_hci_uart_obj.timeout = 2;
-    mp_bluetooth_hci_uart_obj.timeout_char = 2;
-    MP_STATE_PORT(pyb_uart_obj_all)[mp_bluetooth_hci_uart_obj.uart_id - 1] = &mp_bluetooth_hci_uart_obj;
+
+    mp_obj_t args[2];
+    args[0] = MP_OBJ_NEW_SMALL_INT(port);
+    args[1] = MP_OBJ_NEW_SMALL_INT(MICROPY_HW_BLE_UART_BAUDRATE);
+    mp_bluetooth_hci_uart_obj = pyb_uart_type.make_new(&pyb_uart_type, 2, 0, args);
+    mp_bluetooth_hci_uart_obj->is_static = true;
+    mp_bluetooth_hci_uart_obj->timeout = 2;
+    mp_bluetooth_hci_uart_obj->timeout_char = 2;
+    MP_STATE_PORT(pyb_uart_obj_all)[mp_bluetooth_hci_uart_obj->uart_id - 1] = mp_bluetooth_hci_uart_obj;
     return 0;
 }
 
 int mp_bluetooth_hci_uart_set_baudrate(uint32_t baudrate) {
-    uart_init(&mp_bluetooth_hci_uart_obj, baudrate, UART_WORDLENGTH_8B, UART_PARITY_NONE, UART_STOPBITS_1, UART_HWCONTROL_RTS | UART_HWCONTROL_CTS);
-    uart_set_rxbuf(&mp_bluetooth_hci_uart_obj, sizeof(hci_uart_rxbuf), hci_uart_rxbuf);
+    uart_init(mp_bluetooth_hci_uart_obj, baudrate, UART_WORDLENGTH_8B, UART_PARITY_NONE, UART_STOPBITS_1, UART_HWCONTROL_RTS | UART_HWCONTROL_CTS);
+    uart_set_rxbuf(mp_bluetooth_hci_uart_obj, sizeof(hci_uart_rxbuf), hci_uart_rxbuf);
     return 0;
 }
 
 int mp_bluetooth_hci_uart_activate(void) {
     // Interrupt on RX chunk received (idle)
     // Trigger stack poll when this happens
-    mp_obj_t uart_irq_fn = mp_load_attr(MP_OBJ_FROM_PTR(&mp_bluetooth_hci_uart_obj), MP_QSTR_irq);
+    mp_obj_t uart_irq_fn = mp_load_attr(MP_OBJ_FROM_PTR(mp_bluetooth_hci_uart_obj), MP_QSTR_irq);
     mp_obj_t uargs[] = {
         MP_OBJ_FROM_PTR(&mp_uart_interrupt_obj),
         MP_OBJ_NEW_SMALL_INT(UART_FLAG_IDLE),
@@ -181,15 +184,15 @@ int mp_bluetooth_hci_uart_activate(void) {
 
 int mp_bluetooth_hci_uart_write(const uint8_t *buf, size_t len) {
     mp_bluetooth_hci_controller_wakeup();
-    uart_tx_strn(&mp_bluetooth_hci_uart_obj, (void *)buf, len);
+    uart_tx_strn(mp_bluetooth_hci_uart_obj, (void *)buf, len);
     return 0;
 }
 
 // This function expects the controller to be in the wake state via a previous call
 // to mp_bluetooth_hci_controller_woken.
 int mp_bluetooth_hci_uart_readchar(void) {
-    if (uart_rx_any(&mp_bluetooth_hci_uart_obj)) {
-        return uart_rx_char(&mp_bluetooth_hci_uart_obj);
+    if (uart_rx_any(mp_bluetooth_hci_uart_obj)) {
+        return uart_rx_char(mp_bluetooth_hci_uart_obj);
     } else {
         return -1;
     }