diff --git a/ports/nrf/boards/microbit/modules/microbitimage.c b/ports/nrf/boards/microbit/modules/microbitimage.c
index ae3af5639347af886f2beb86f6191d9b3d5b1c83..046b9255cfb2da1b6e0490d3ae5ba7a8ab1caebc 100644
--- a/ports/nrf/boards/microbit/modules/microbitimage.c
+++ b/ports/nrf/boards/microbit/modules/microbitimage.c
@@ -605,9 +605,9 @@ microbit_image_obj_t *microbit_image_for_char(char c) {
     return (microbit_image_obj_t *)result;
 }
 
-#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
+#if MICROPY_PY_BUILTINS_FLOAT
 microbit_image_obj_t *microbit_image_dim(microbit_image_obj_t *lhs, mp_float_t fval) {
-#else // MICROPY_FLOAT_IMPL_NONE
+#else
 microbit_image_obj_t *microbit_image_dim(microbit_image_obj_t *lhs, mp_int_t fval) {
 #endif
     if (fval < 0) 
@@ -615,9 +615,9 @@ microbit_image_obj_t *microbit_image_dim(microbit_image_obj_t *lhs, mp_int_t fva
     greyscale_t *result = greyscale_new(imageWidth(lhs), imageHeight(lhs));
     for (int x = 0; x < imageWidth(lhs); ++x) {
         for (int y = 0; y < imageWidth(lhs); ++y) {
-#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
+#if MICROPY_PY_BUILTINS_FLOAT
             int val = min((int)imageGetPixelValue(lhs, x,y)*fval+0.5, MAX_BRIGHTNESS);
-#else // MICROPY_FLOAT_IMPL_NONE
+#else
             int val = min((int)imageGetPixelValue(lhs, x,y)*fval, MAX_BRIGHTNESS);
 #endif
             greyscaleSetPixelValue(result, x, y, val);
@@ -659,13 +659,13 @@ STATIC mp_obj_t image_binary_op(mp_binary_op_t op, mp_obj_t lhs_in, mp_obj_t rhs
     case MP_BINARY_OP_SUBTRACT:
         break;
     case MP_BINARY_OP_MULTIPLY:
-#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
+#if MICROPY_PY_BUILTINS_FLOAT
         return microbit_image_dim(lhs, mp_obj_get_float(rhs_in));
 #else
         return microbit_image_dim(lhs, mp_obj_get_int(rhs_in) * 10);
 #endif
     case MP_BINARY_OP_TRUE_DIVIDE:
-#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
+#if MICROPY_PY_BUILTINS_FLOAT
         return microbit_image_dim(lhs, 1.0/mp_obj_get_float(rhs_in));
 #else
         break;
diff --git a/ports/nrf/boards/microbit/modules/microbitimage.h b/ports/nrf/boards/microbit/modules/microbitimage.h
index 823d19abda17c8e07f282c0492da23b90ef41067..23edbd6baac2d27f8aaa9c558540d2f63a9eab56 100644
--- a/ports/nrf/boards/microbit/modules/microbitimage.h
+++ b/ports/nrf/boards/microbit/modules/microbitimage.h
@@ -89,7 +89,7 @@ extern const mp_obj_type_t microbit_image_type;
 #define HEART_IMAGE (microbit_image_obj_t *)(&microbit_const_image_heart_obj)
 #define HAPPY_IMAGE (microbit_image_obj_t *)(&microbit_const_image_happy_obj)
 
-#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
+#if MICROPY_PY_BUILTINS_FLOAT
 microbit_image_obj_t *microbit_image_dim(microbit_image_obj_t *lhs, mp_float_t fval);
 #else
 microbit_image_obj_t *microbit_image_dim(microbit_image_obj_t *lhs, mp_int_t val);
diff --git a/ports/nrf/boards/microbit/modules/modmicrobit.c b/ports/nrf/boards/microbit/modules/modmicrobit.c
index bb8983b4e5ef2ced1444c67ec1072e882591eb15..061e095f6a7448e96c3c35398fe314c7d470ef1a 100644
--- a/ports/nrf/boards/microbit/modules/modmicrobit.c
+++ b/ports/nrf/boards/microbit/modules/modmicrobit.c
@@ -45,7 +45,7 @@ STATIC mp_obj_t microbit_sleep(mp_obj_t ms_in) {
     mp_int_t ms = 0;
     if (mp_obj_is_integer(ms_in)) {
         ms = mp_obj_get_int(ms_in);
-#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
+#if MICROPY_PY_BUILTINS_FLOAT
     } else {
         ms = (mp_int_t)mp_obj_get_float(ms_in);
 #endif
@@ -97,7 +97,7 @@ MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(microbit_panic_obj, 0, 1, microbit_panic);
 
 STATIC mp_obj_t microbit_temperature(void) {
     int temp = nrf_temp_read();
-#if MICROPY_FLOAT_IMPL == MICROPY_FLOAT_IMPL_FLOAT
+#if MICROPY_PY_BUILTINS_FLOAT
     return mp_obj_new_float(temp / 4);
 #else
     return mp_obj_new_int(temp / 4);