diff --git a/ports/stm32/mpconfigport.h b/ports/stm32/mpconfigport.h
index 3147e28681..47795c4e71 100644
--- a/ports/stm32/mpconfigport.h
+++ b/ports/stm32/mpconfigport.h
@@ -60,6 +60,12 @@
 #define MICROPY_OPT_COMPUTED_GOTO   (1)
 #endif
 #define MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE (0)
+#ifndef MICROPY_OPT_LOAD_ATTR_FAST_PATH
+#define MICROPY_OPT_LOAD_ATTR_FAST_PATH (1)
+#endif
+#ifndef MICROPY_OPT_MAP_LOOKUP_CACHE
+#define MICROPY_OPT_MAP_LOOKUP_CACHE (__CORTEX_M > 0)
+#endif
 #define MICROPY_OPT_MPZ_BITWISE     (1)
 #define MICROPY_OPT_MATH_FACTORIAL  (1)