diff --git a/subjects/doop.en.md b/subjects/doop.en.md
index 0c80924de..00fd0db6a 100644
--- a/subjects/doop.en.md
+++ b/subjects/doop.en.md
@@ -35,4 +35,6 @@ student@ubuntu:~/piscine-go/test$ ./doop 1 % 0 | cat -e
 No Modulo by 0$
 student@ubuntu:~/piscine-go/test$ ./doop 1 "*" 1
 1
+student@ubuntu:~/piscine-go/test$ ./doop 1 "*" -1
+-1
 ```