diff --git a/ports/atmel-samd/mpconfigport.h b/ports/atmel-samd/mpconfigport.h
index ed10da9b9d..bce89e0b99 100644
--- a/ports/atmel-samd/mpconfigport.h
+++ b/ports/atmel-samd/mpconfigport.h
@@ -42,6 +42,7 @@
 #define CIRCUITPY_MCU_FAMILY                        samd21
 #define MICROPY_PY_SYS_PLATFORM                     "Atmel SAMD21"
 #define SPI_FLASH_MAX_BAUDRATE 8000000
+#define MICROPY_PY_BUILTINS_COMPLEX                 (0)
 #define MICROPY_PY_BUILTINS_NOTIMPLEMENTED          (0)
 #define MICROPY_PY_FUNCTION_ATTRS                   (0)
 // MICROPY_PY_UJSON depends on MICROPY_PY_IO
diff --git a/py/circuitpy_mpconfig.h b/py/circuitpy_mpconfig.h
index 799217777c..4b847de38b 100644
--- a/py/circuitpy_mpconfig.h
+++ b/py/circuitpy_mpconfig.h
@@ -188,7 +188,9 @@ typedef long mp_off_t;
 #define MICROPY_COMP_FSTRING_LITERAL          (MICROPY_CPYTHON_COMPAT)
 #define MICROPY_MODULE_WEAK_LINKS             (0)
 #define MICROPY_PY_ALL_SPECIAL_METHODS        (CIRCUITPY_FULL_BUILD)
+#ifndef MICROPY_PY_BUILTINS_COMPLEX
 #define MICROPY_PY_BUILTINS_COMPLEX           (CIRCUITPY_FULL_BUILD)
+#endif
 #define MICROPY_PY_BUILTINS_FROZENSET         (CIRCUITPY_FULL_BUILD)
 #define MICROPY_PY_BUILTINS_STR_CENTER        (CIRCUITPY_FULL_BUILD)
 #define MICROPY_PY_BUILTINS_STR_PARTITION     (CIRCUITPY_FULL_BUILD)