diff --git a/server/knowledge_base/kb_service/base.py b/server/knowledge_base/kb_service/base.py
index 9af5b0e..8d1de48 100644
--- a/server/knowledge_base/kb_service/base.py
+++ b/server/knowledge_base/kb_service/base.py
@@ -157,6 +157,7 @@ class KBService(ABC):
     def do_search(self,
                   query: str,
                   top_k: int,
+                  score_threshold: float,
                   embeddings: Embeddings,
                   ) -> List[Document]:
         """
diff --git a/server/knowledge_base/kb_service/pg_kb_service.py b/server/knowledge_base/kb_service/pg_kb_service.py
index 38d8065..6876bd8 100644
--- a/server/knowledge_base/kb_service/pg_kb_service.py
+++ b/server/knowledge_base/kb_service/pg_kb_service.py
@@ -43,7 +43,7 @@ class PGKBService(KBService):
             '''))
             connect.commit()
 
-    def do_search(self, query: str, top_k: int, embeddings: Embeddings):
+    def do_search(self, query: str, top_k: int, score_threshold: float, embeddings: Embeddings):
         # todo: support score threshold
         self._load_pg_vector(embeddings=embeddings)
         return self.pg_vector.similarity_search_with_score(query, top_k)