diff --git a/main.s65 b/main.s65
index 872ca6d..a155834 100644
--- a/main.s65
+++ b/main.s65
@@ -238,6 +238,7 @@ str_io2:
 ; reset vector
 ;********************************************************************************
 .segment "RESET_VECTOR"
+.assert * = $fffa,error,"Reset vector not at $8ffa"
     .word nmi     
     .word reset
     .word irq