diff --git a/ports/mimxrt/modmimxrt.c b/ports/mimxrt/modmimxrt.c
index 041a72f7f7..0091c36ffb 100644
--- a/ports/mimxrt/modmimxrt.c
+++ b/ports/mimxrt/modmimxrt.c
@@ -41,3 +41,5 @@ const mp_obj_module_t mp_module_mimxrt = {
     .base = { &mp_type_module },
     .globals = (mp_obj_dict_t *)&mimxrt_module_globals,
 };
+
+MP_REGISTER_MODULE(MP_QSTR_mimxrt, mp_module_mimxrt, 1);
diff --git a/ports/mimxrt/modutime.c b/ports/mimxrt/modutime.c
index 822e2771d2..f24ce43c0f 100644
--- a/ports/mimxrt/modutime.c
+++ b/ports/mimxrt/modutime.c
@@ -134,3 +134,5 @@ const mp_obj_module_t mp_module_utime = {
     .base = { &mp_type_module },
     .globals = (mp_obj_dict_t *)&time_module_globals,
 };
+
+MP_REGISTER_MODULE(MP_QSTR_utime, mp_module_utime, 1);
diff --git a/ports/mimxrt/mpconfigport.h b/ports/mimxrt/mpconfigport.h
index 1569268cd9..05de0306b4 100644
--- a/ports/mimxrt/mpconfigport.h
+++ b/ports/mimxrt/mpconfigport.h
@@ -228,9 +228,6 @@ static inline void restore_irq_pri(uint32_t basepri) {
 #define MICROPY_PORT_BUILTINS \
     { MP_ROM_QSTR(MP_QSTR_open), MP_ROM_PTR(&mp_builtin_open_obj) },
 
-extern const struct _mp_obj_module_t mp_module_mimxrt;
-extern const struct _mp_obj_module_t mp_module_utime;
-
 #if defined(MICROPY_HW_ETH_MDC)
 extern const struct _mp_obj_type_t network_lan_type;
 #define MICROPY_HW_NIC_ETH                  { MP_ROM_QSTR(MP_QSTR_LAN), MP_ROM_PTR(&network_lan_type) },
@@ -238,10 +235,6 @@ extern const struct _mp_obj_type_t network_lan_type;
 #define MICROPY_HW_NIC_ETH
 #endif
 
-#define MICROPY_PORT_BUILTIN_MODULES \
-    { MP_ROM_QSTR(MP_QSTR_mimxrt), (mp_obj_t)&mp_module_mimxrt }, \
-    { MP_ROM_QSTR(MP_QSTR_utime), MP_ROM_PTR(&mp_module_utime) }, \
-
 #ifndef MICROPY_BOARD_NETWORK_INTERFACES
 #define MICROPY_BOARD_NETWORK_INTERFACES
 #endif