diff --git a/libs/kotaemon/kotaemon/indices/qa/citation.py b/libs/kotaemon/kotaemon/indices/qa/citation.py
index 91f496162..922e576af 100644
--- a/libs/kotaemon/kotaemon/indices/qa/citation.py
+++ b/libs/kotaemon/kotaemon/indices/qa/citation.py
@@ -105,9 +105,9 @@ def invoke(self, context: str, question: str):
             print("CitationPipeline: finish invoking LLM")
             if not llm_output.messages:
                 return None
-            function_output = llm_output.messages[0].additional_kwargs["tool_calls"][0]["function"][
-                "arguments"
-            ]
+            function_output = llm_output.messages[0].additional_kwargs["tool_calls"][0][
+                "function"
+            ]["arguments"]
             output = QuestionAnswer.parse_raw(function_output)
         except Exception as e:
             print(e)
@@ -122,9 +122,9 @@ async def ainvoke(self, context: str, question: str):
             print("CitationPipeline: async invoking LLM")
             llm_output = await self.get_from_path("llm").ainvoke(messages, **llm_kwargs)
             print("CitationPipeline: finish async invoking LLM")
-            function_output = llm_output.messages[0].additional_kwargs["tool_calls"][0]["function"][
-                "arguments"
-            ]
+            function_output = llm_output.messages[0].additional_kwargs["tool_calls"][0][
+                "function"
+            ]["arguments"]
             output = QuestionAnswer.parse_raw(function_output)
         except Exception as e:
             print(e)