diff --git a/src/backend/base/langflow/api/v1/chat.py b/src/backend/base/langflow/api/v1/chat.py
index 2e53818ef..2d7522834 100644
--- a/src/backend/base/langflow/api/v1/chat.py
+++ b/src/backend/base/langflow/api/v1/chat.py
@@ -188,7 +188,7 @@ async def build_vertex(
             params = format_exception_message(exc)
             valid = False
             output_label = vertex.outputs[0]["name"] if vertex.outputs else "output"
-            logs = {output_label: [Log(message=params, type="error")]}
+            logs = {output_label: Log(message=params, type="error")}
             result_data_response = ResultDataResponse(results={}, logs=logs)
             artifacts = {}
             # If there's an error building the vertex