diff --git a/litellm/responses/litellm_completion_transformation/transformation.py b/litellm/responses/litellm_completion_transformation/transformation.py
index bd239922fd3..593d9803c1b 100644
--- a/litellm/responses/litellm_completion_transformation/transformation.py
+++ b/litellm/responses/litellm_completion_transformation/transformation.py
@@ -2606,7 +2606,7 @@ class LiteLLMCompletionResponsesConfig:
                                 if text
                             ],
                             encrypted_content=encrypted_content,
-                        )
+                        ).model_copy(update={"summary": []})
                     ]
         return []
 
diff --git a/tests/unit/responses/litellm_completion_transformation/test_litellm_completion_responses.py b/tests/unit/responses/litellm_completion_transformation/test_litellm_completion_responses.py
index 7b9de4644b4..acf638e2873 100644
--- a/tests/unit/responses/litellm_completion_transformation/test_litellm_completion_responses.py
+++ b/tests/unit/responses/litellm_completion_transformation/test_litellm_completion_responses.py
@@ -4939,6 +4939,24 @@ class TestBridgedOutputItemIdPrefixes:
             choices=[choice],
         )
 
+    def test_reasoning_item_includes_empty_summary(self):
+        item: Final = self._reasoning_items()[0]
+
+        assert item.model_dump(exclude_none=True) == {
+            "type": "reasoning",
+            "id": item.id,
+            "status": "completed",
+            "role": "assistant",
+            "content": [
+                {
+                    "type": "output_text",
+                    "text": "thinking about fruit",
+                    "annotations": [],
+                }
+            ],
+            "summary": [],
+        }
+
     def test_reasoning_item_id_uses_rs_prefix(self):
         items = self._reasoning_items()