diff --git a/metagpt/memory/memory.py b/metagpt/memory/memory.py
index d44753413..0707a36ea 100644
--- a/metagpt/memory/memory.py
+++ b/metagpt/memory/memory.py
@@ -7,13 +7,14 @@
 @Modified By: mashenquan, 2023-11-1. According to RFC 116: Updated the type of index key.
 """
 from collections import defaultdict
-from typing import DefaultDict, Iterable, Set
+from typing import DefaultDict, Iterable, Optional, Set
 
 from pydantic import BaseModel, Field, SerializeAsAny
 
 from metagpt.const import IGNORED_MESSAGE_ID
 from metagpt.schema import Message
 from metagpt.utils.common import any_to_str, any_to_str_set
+from metagpt.utils.exceptions import handle_exception
 
 
 class Memory(BaseModel):
@@ -105,6 +106,7 @@ class Memory(BaseModel):
             rsp += self.index[action]
         return rsp
 
-    def get_by_position(self, position: int) -> Message:
-        """Return the message by its position"""
+    @handle_exception
+    def get_by_position(self, position: int) -> Optional[Message]:
+        """Returns the message at the given position if valid, otherwise returns None"""
         return self.storage[position]