diff --git a/cv4/a_train.c b/cv4/a_train.c
index bfc56f4..4e252b2 100644
--- a/cv4/a_train.c
+++ b/cv4/a_train.c
@@ -89,6 +89,7 @@ struct car* clear_train(struct car* first, const char* target)
         else if(!strcmp(prev->next->value, target))
         {
             free(prev->next);
+            prev->next = NULL;
             return first;
         }
         else