diff --git a/cv9/snake.c b/cv9/snake.c
index 7205579..a2ae686 100644
--- a/cv9/snake.c
+++ b/cv9/snake.c
@@ -1,5 +1,6 @@
 #include "snake.h"
 #include <stdlib.h>
+#include <assert.h>
 
 struct snake* add_snake(struct snake* snake,int x,int y){
     struct snake* hlavicka = calloc(1,sizeof(struct snake));
@@ -20,7 +21,7 @@ struct snake* remove_snake(struct snake* snake){
     struct snake* nova_hlavicka = snake->next;
 
     free(snake);
-    
+
     assert(nova_hlavicka == NULL || nova_hlavicka->next == NULL);
 
     return nova_hlavicka;