diff --git a/ports/stm32/boardctrl.c b/ports/stm32/boardctrl.c
index f1b7a4e81c..fa71d8e7f4 100644
--- a/ports/stm32/boardctrl.c
+++ b/ports/stm32/boardctrl.c
@@ -155,6 +155,8 @@ int boardctrl_run_boot_py(boardctrl_state_t *state) {
             return BOARDCTRL_GOTO_SOFT_RESET_EXIT;
         }
         if (!ret) {
+            // There was an error, prevent main.py from running and flash LEDs.
+            state->reset_mode = BOARDCTRL_RESET_MODE_SAFE_MODE;
             flash_error(4);
         }
     }