diff --git a/py/persistentcode.c b/py/persistentcode.c
index 82ef0c499..1b1741f26 100644
--- a/py/persistentcode.c
+++ b/py/persistentcode.c
@@ -402,7 +402,13 @@ mp_compiled_module_t mp_raw_code_load(mp_reader_t *reader, mp_module_context_t *
     if (MPY_FEATURE_DECODE_ARCH(header[2]) != MP_NATIVE_ARCH_NONE) {
         byte arch = MPY_FEATURE_DECODE_ARCH(header[2]);
         if (!MPY_FEATURE_ARCH_TEST(arch)) {
-            mp_raise_ValueError(MP_ERROR_TEXT("incompatible .mpy arch"));
+            if (MPY_FEATURE_ARCH_TEST(MP_NATIVE_ARCH_NONE)) {
+                // On supported ports this can be resolved by enabling feature, eg
+                // mpconfigboard.h: MICROPY_EMIT_THUMB (1)
+                mp_raise_ValueError(MP_ERROR_TEXT("native code in .mpy unsupported"));
+            } else {
+                mp_raise_ValueError(MP_ERROR_TEXT("incompatible .mpy arch"));
+            }
         }
     }