diff --git a/libs/core/langchain_core/messages/ai.py b/libs/core/langchain_core/messages/ai.py
index 011c1d2ed46..ccaf1f04ef0 100644
--- a/libs/core/langchain_core/messages/ai.py
+++ b/libs/core/langchain_core/messages/ai.py
@@ -545,6 +545,9 @@ class AIMessageChunk(AIMessage, BaseMessageChunk):
                     and call_id in id_to_tc
                 ):
                     self.content[idx] = cast("dict[str, Any]", id_to_tc[call_id])
+                    if "extras" in block:
+                        # mypy does not account for instance check for dict above
+                        self.content[idx]["extras"] = block["extras"]  # type: ignore[index]
 
         return self
 
diff --git a/libs/core/tests/unit_tests/messages/test_ai.py b/libs/core/tests/unit_tests/messages/test_ai.py
index a65033f82c1..6ced0a59e08 100644
--- a/libs/core/tests/unit_tests/messages/test_ai.py
+++ b/libs/core/tests/unit_tests/messages/test_ai.py
@@ -358,6 +358,8 @@ def test_content_blocks() -> None:
 
     # test v1 content
     chunk_1.content = cast("str | list[str | dict]", chunk_1.content_blocks)
+    assert len(chunk_1.content) == 1
+    chunk_1.content[0]["extras"] = {"baz": "qux"}  # type: ignore[index]
     chunk_1.response_metadata["output_version"] = "v1"
     chunk_2.content = cast("str | list[str | dict]", chunk_2.content_blocks)
 
@@ -368,6 +370,7 @@ def test_content_blocks() -> None:
             "name": "foo",
             "args": {"foo": "bar"},
             "id": "abc_123",
+            "extras": {"baz": "qux"},
         }
     ]