diff --git a/cv9/snake.c b/cv9/snake.c
index b5a963d..5549d4d 100644
--- a/cv9/snake.c
+++ b/cv9/snake.c
@@ -32,6 +32,11 @@ struct snake* remove_snake(struct snake* snake){
 }
 
 void free_snake(struct snake* sn){
+    if (sn == NULL) {
+        return;
+    }
+    free_snake(sn->next);
+    free(sn);
 }
 
 int is_snake(struct snake* snake,int x,int y){