diff --git a/simulat0r/firmware/basic/xxtea.c b/simulat0r/firmware/basic/xxtea.c
index 77604be..c315d35 100644
--- a/simulat0r/firmware/basic/xxtea.c
+++ b/simulat0r/firmware/basic/xxtea.c
@@ -1,2 +1,4 @@
-/* AUTOGENERATED SOURCE FILE */
+/* use SAFE version instead of ARM asm */
+#define SAFE
+
 #include "../../../firmware/basic/xxtea.c"