diff --git a/du3/program.c b/du3/program.c
index 95cfa85..3bfdc0c 100644
--- a/du3/program.c
+++ b/du3/program.c
@@ -49,7 +49,7 @@ int check(char* input) {
             break;
             case '/':
              if (number2 == 0) {
-                 return 0;
+                 return -1;
               } else { resultat = number1 / number2; 
                  }
                 break;