diff --git a/ports/samd/mcu/samd21/mpconfigmcu.h b/ports/samd/mcu/samd21/mpconfigmcu.h
index fdad3fee4a..fbb5b28e2b 100644
--- a/ports/samd/mcu/samd21/mpconfigmcu.h
+++ b/ports/samd/mcu/samd21/mpconfigmcu.h
@@ -63,12 +63,20 @@ unsigned long trng_random_u32(int delay);
 #define MICROPY_PY_BUILTINS_ROUND_INT   (SAMD21_EXTRA_FEATURES)
 #define MICROPY_CAN_OVERRIDE_BUILTINS   (SAMD21_EXTRA_FEATURES)
 #define MICROPY_PY_SYS_STDIO_BUFFER     (SAMD21_EXTRA_FEATURES)
+#ifndef MICROPY_PY_FRAMEBUF
 #define MICROPY_PY_FRAMEBUF             (SAMD21_EXTRA_FEATURES)
+#endif
+#ifndef MICROPY_PY_ASYNCIO
 #define MICROPY_PY_ASYNCIO              (SAMD21_EXTRA_FEATURES)
+#endif
+#ifndef MICROPY_PY_SELECT
 #define MICROPY_PY_SELECT               (SAMD21_EXTRA_FEATURES)
+#endif
 #define MICROPY_PY_ERRNO                (SAMD21_EXTRA_FEATURES)
 #define MICROPY_PY_DEFLATE              (SAMD21_EXTRA_FEATURES)
+#ifndef MICROPY_PY_ONEWIRE
 #define MICROPY_PY_ONEWIRE              (SAMD21_EXTRA_FEATURES)
+#endif
 
 #ifndef MICROPY_PY_MACHINE_PIN_BOARD_CPU
 #define MICROPY_PY_MACHINE_PIN_BOARD_CPU (1)