diff --git a/go/tests/doop_test/doop_correct/main.go b/go/tests/doop_test/doop_correct/main.go
index d1c06328..b882bacb 100644
--- a/go/tests/doop_test/doop_correct/main.go
+++ b/go/tests/doop_test/doop_correct/main.go
@@ -10,35 +10,27 @@ func main() {
 	if len(os.Args) == 4 {
 		a, err := strconv.Atoi(os.Args[1])
 		if err != nil {
-			fmt.Println(0)
 			return
 		}
 		b, err := strconv.Atoi(os.Args[3])
 		if err != nil {
-			fmt.Println(0)
 			return
 		}
 		operator := os.Args[2]
 		switch operator {
 		case "+":
 			result := a + b
-			if (result > a) != (b > 0) {
-				fmt.Println(0)
-			} else {
+			if (result > a) == (b > 0) {
 				fmt.Println(result)
 			}
 		case "-":
 			result := a - b
-			if (result < a) != (b > 0) {
-				fmt.Println(0)
-			} else {
+			if (result < a) == (b > 0) {
 				fmt.Println(result)
 			}
 		case "*":
 			result := a * b
-			if a != 0 && (result/a != b) {
-				fmt.Println(0)
-			} else {
+			if a == 0 || (result/a == b) {
 				fmt.Println(result)
 			}
 		case "/":
diff --git a/subjects/doop.en.md b/subjects/doop.en.md
index 63476d15..a5b61964 100644
--- a/subjects/doop.en.md
+++ b/subjects/doop.en.md
@@ -7,16 +7,10 @@ Write a program that is called `doop`.
 The program has to be used with three arguments:
 
 - A value
-- An operator
+- An operator, one of : `+`, `-`, `/`, `*`, `%`
 - Another value
 
-You should use `int64`.
-
-The following operators are considered valid: `+`, `-`, `/`, `*`, `%`.
-
-In case of an invalid operator or overflow the programs prints `0`.
-
-In case of an invalid number of arguments the program prints nothing.
+In case of an invalid operator, value, number of arguments or an overflow the programs prints nothing.
 
 The program has to handle the modulo and division operations by 0 as shown on the output examples below.
 
@@ -27,10 +21,8 @@ student@ubuntu:~/[[ROOT]]/test$ go build doop.go
 student@ubuntu:~/[[ROOT]]/test$ ./doop
 student@ubuntu:~/[[ROOT]]/test$ ./doop 1 + 1 | cat -e
 2$
-student@ubuntu:~/[[ROOT]]/test$ ./doop hello + 1 | cat -e
-0$
-student@ubuntu:~/[[ROOT]]/test$ ./doop 1 p 1 | cat -e
-0$
+student@ubuntu:~/[[ROOT]]/test$ ./doop hello + 1
+student@ubuntu:~/[[ROOT]]/test$ ./doop 1 p 1
 student@ubuntu:~/[[ROOT]]/test$ ./doop 1 / 0 | cat -e
 No division by 0$
 student@ubuntu:~/[[ROOT]]/test$ ./doop 1 % 0 | cat -e