diff --git a/rag2_0/dify/dify_tool.py b/rag2_0/dify/dify_tool.py
index d76bcb1..d881d99 100755
--- a/rag2_0/dify/dify_tool.py
+++ b/rag2_0/dify/dify_tool.py
@@ -279,7 +279,7 @@ class DifyTool:
     """
 
     def __init__(self):
-        self.dify_pgsql = PgSql()
+        self.dify_pgsql = DifyTool.PgSql()
 
     def __del__(self):
         """