diff --git a/ports/teensy/mpconfigport.h b/ports/teensy/mpconfigport.h
index e57fae15e9..f67eb66fab 100644
--- a/ports/teensy/mpconfigport.h
+++ b/ports/teensy/mpconfigport.h
@@ -41,9 +41,6 @@ extern const struct _mp_obj_module_t pyb_module;
 
 #define MP_STATE_PORT MP_STATE_VM
 
-#define MICROPY_PORT_ROOT_POINTERS \
-    struct _pyb_uart_obj_t *pyb_stdio_uart; \
-
 // type definitions for the specific machine
 
 #define UINT_FMT "%u"
diff --git a/ports/teensy/teensy_hal.c b/ports/teensy/teensy_hal.c
index 342e7c6501..93103319b5 100644
--- a/ports/teensy/teensy_hal.c
+++ b/ports/teensy/teensy_hal.c
@@ -77,3 +77,5 @@ void mp_hal_gpio_clock_enable(GPIO_TypeDef *gpio) {
 void extint_register_pin(const void *pin, uint32_t mode, int hard_irq, mp_obj_t callback_obj) {
     mp_raise_NotImplementedError(NULL);
 }
+
+MP_REGISTER_ROOT_POINTER(struct _pyb_uart_obj_t *pyb_stdio_uart);