diff --git a/instaloader/nodeiterator.py b/instaloader/nodeiterator.py
index a49656d..bd9d4e1 100644
--- a/instaloader/nodeiterator.py
+++ b/instaloader/nodeiterator.py
@@ -77,7 +77,7 @@ class NodeIterator(Iterator[T]):
                  query_variables: Optional[Dict[str, Any]] = None,
                  query_referer: Optional[str] = None,
                  first_data: Optional[Dict[str, Any]] = None,
-                 is_first: Optional[Callable[[T], bool]] = None):
+                 is_first: Optional[Callable[[T, Optional[T]], bool]] = None):
         self._context = context
         self._query_hash = query_hash
         self._edge_extractor = edge_extractor
@@ -131,7 +131,7 @@ class NodeIterator(Iterator[T]):
                 raise
             item = self._node_wrapper(node)
             if self._is_first is not None:
-                if self._is_first(item):
+                if self._is_first(item, self.first_item):
                     self._first_node = node
             else:
                 if self._first_node is None:
diff --git a/instaloader/structures.py b/instaloader/structures.py
index 46f6fe2..109c845 100644
--- a/instaloader/structures.py
+++ b/instaloader/structures.py
@@ -1039,17 +1039,8 @@ class Profile:
         )
 
     @staticmethod
-    def _make_is_newest_checker() -> Callable[[Post], bool]:
-        newest_date: Optional[datetime] = None
-        def is_newest(p: Post) -> bool:
-            nonlocal newest_date
-            post_date = p.date_local
-            if newest_date is None or post_date > newest_date:
-                newest_date = post_date
-                return True
-            else:
-                return False
-        return is_newest
+    def _make_is_newest_checker() -> Callable[[Post, Optional[Post]], bool]:
+        return lambda post, first: first is None or post.date_local > first.date_local
 
     def get_followers(self) -> NodeIterator['Profile']:
         """