diff --git a/kb_workflow/srt/semantic_engine.py b/kb_workflow/srt/semantic_engine.py
index 0827e7d..77b6de8 100644
--- a/kb_workflow/srt/semantic_engine.py
+++ b/kb_workflow/srt/semantic_engine.py
@@ -581,7 +581,7 @@ class UnifiedSegmentationStrategy:
         from kb_workflow.srt.parser import Segment
 
         virtual_segment = Segment(
-            index=1,
+            id=1,
             start_time=0.0,
             end_time=1.0,
             text=chunk_text