diff --git a/appendix/appendix-a-trap.md b/appendix/appendix-a-trap.md
index c3fe6c3..719a859 100644
--- a/appendix/appendix-a-trap.md
+++ b/appendix/appendix-a-trap.md
@@ -190,6 +190,7 @@ func main() {
 		for i := 0; i < 10; i++ {
 			fmt.Println(i)
 		}
+		os.Exit(0)
 	}()
 
 	select{}