diff --git a/cv9/snake.c b/cv9/snake.c
index 9852808..75614e6 100644
--- a/cv9/snake.c
+++ b/cv9/snake.c
@@ -37,7 +37,7 @@ void free_snake(struct snake* sn){
 
 int is_snake(struct snake* snake,int x,int y){
     struct snake* this = snake;	
-	while (this->next != NULL){
+	while (this != NULL){
 		
 		if(this->x == x && this->y == y){
 			return 1;