diff --git a/stmhal/i2c.c b/stmhal/i2c.c
index eb6716ce39..82f70471a9 100644
--- a/stmhal/i2c.c
+++ b/stmhal/i2c.c
@@ -349,7 +349,7 @@ STATIC void pyb_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_ki
 ///   - `gencall` is whether to support general call mode
 STATIC mp_obj_t pyb_i2c_init_helper(const pyb_i2c_obj_t *self, mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
     static const mp_arg_t allowed_args[] = {
-        { MP_QSTR_mode,     MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
+        { MP_QSTR_mode,     MP_ARG_INT, {.u_int = PYB_I2C_MASTER} },
         { MP_QSTR_addr,     MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0x12} },
         { MP_QSTR_baudrate, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = MICROPY_HW_I2C_BAUDRATE_DEFAULT} },
         { MP_QSTR_gencall,  MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false} },
diff --git a/stmhal/modmachine.c b/stmhal/modmachine.c
index 6a0c4a9fc0..c495573fb1 100644
--- a/stmhal/modmachine.c
+++ b/stmhal/modmachine.c
@@ -39,6 +39,8 @@
 #include "pin.h"
 #include "timer.h"
 #include "usb.h"
+#include "i2c.h"
+#include "spi.h"
 
 // machine.info([dump_alloc_table])
 // Print out lots of information about the board.
@@ -417,8 +419,12 @@ STATIC const mp_map_elem_t machine_module_globals_table[] = {
 #if 0
     { MP_OBJ_NEW_QSTR(MP_QSTR_RTC),                 (mp_obj_t)&pyb_rtc_type },
     { MP_OBJ_NEW_QSTR(MP_QSTR_ADC),                 (mp_obj_t)&pyb_adc_type },
+#endif
+    // TODO: Per new API, both types below, if called with 1 arg (ID), should still
+    // initialize master mode on the peripheral.
     { MP_OBJ_NEW_QSTR(MP_QSTR_I2C),                 (mp_obj_t)&pyb_i2c_type },
     { MP_OBJ_NEW_QSTR(MP_QSTR_SPI),                 (mp_obj_t)&pyb_spi_type },
+#if 0
     { MP_OBJ_NEW_QSTR(MP_QSTR_UART),                (mp_obj_t)&pyb_uart_type },
     { MP_OBJ_NEW_QSTR(MP_QSTR_Timer),               (mp_obj_t)&pyb_timer_type },
     { MP_OBJ_NEW_QSTR(MP_QSTR_WDT),                 (mp_obj_t)&pyb_wdt_type },