diff --git a/c-cpp/06_linkedlist/single_list.c b/c-cpp/06_linkedlist/single_list.c
index 82ae084..346d31d 100644
--- a/c-cpp/06_linkedlist/single_list.c
+++ b/c-cpp/06_linkedlist/single_list.c
@@ -46,7 +46,7 @@ struct single_list* del(struct single_list **prev)
 
 	if (!prev)
 		return NULL;
-	if (*prev == null)
+	if (*prev == NULL)
 		return NULL;
 	tmp = *prev;
 	*prev = (*prev)->next;