diff --git a/py/circuitpy_mpconfig.h b/py/circuitpy_mpconfig.h
index b8dbcd6de2..43f2726e51 100644
--- a/py/circuitpy_mpconfig.h
+++ b/py/circuitpy_mpconfig.h
@@ -188,7 +188,9 @@ typedef long mp_off_t;
 
 // Turning off FULL_BUILD removes some functionality to reduce flash size on tiny SAMD21s
 #define MICROPY_BUILTIN_METHOD_CHECK_SELF_ARG (CIRCUITPY_FULL_BUILD)
+#ifndef MICROPY_CPYTHON_COMPAT
 #define MICROPY_CPYTHON_COMPAT                (CIRCUITPY_FULL_BUILD)
+#endif
 #define MICROPY_PY_BUILTINS_POW3              (CIRCUITPY_BUILTINS_POW3)
 #define MICROPY_COMP_FSTRING_LITERAL          (MICROPY_CPYTHON_COMPAT)
 #define MICROPY_MODULE_WEAK_LINKS             (0)