diff --git a/agent/native_compaction.py b/agent/native_compaction.py
index 364cc1ecea..09dd1cc30f 100644
--- a/agent/native_compaction.py
+++ b/agent/native_compaction.py
@@ -206,7 +206,7 @@ def _truncate_input_text_parts(content: List[Dict[str, Any]], budget: int) -> Li
             if lo:
                 head.append({**part, "text": text[:lo]})
             break
-        head.append({**part})
+        head.append(part)
         budget -= cost
     return head