diff --git a/stmhal/mpconfigport.h b/stmhal/mpconfigport.h
index ad3599ee8..2e5d50b2a 100644
--- a/stmhal/mpconfigport.h
+++ b/stmhal/mpconfigport.h
@@ -42,7 +42,7 @@
 #define MICROPY_LONGINT_IMPL        (MICROPY_LONGINT_IMPL_MPZ)
 #define MICROPY_FLOAT_IMPL          (MICROPY_FLOAT_IMPL_FLOAT)
 #define MICROPY_OPT_COMPUTED_GOTO   (1)
-#define MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE (1)
+#define MICROPY_OPT_CACHE_MAP_LOOKUP_IN_BYTECODE (0)
 /* Enable FatFS LFNs
     0: Disable LFN feature.
     1: Enable LFN with static working buffer on the BSS. Always NOT reentrant.