diff --git a/deepdoc/parser/ppt_parser.py b/deepdoc/parser/ppt_parser.py
index 58a983266..39eab03a6 100644
--- a/deepdoc/parser/ppt_parser.py
+++ b/deepdoc/parser/ppt_parser.py
@@ -87,7 +87,7 @@ class RAGFlowPptParser:
                 break
             texts = []
             for shape in sorted(
-                    slide.shapes, key=lambda x: ((x.top if x.top is not None else 0) // 10, x.left)):
+                    slide.shapes, key=lambda x: ((x.top if x.top is not None else 0) // 10, x.left if x.left is not None else 0)):
                 try:
                     txt = self.__extract(shape)
                     if txt:
@@ -96,4 +96,4 @@ class RAGFlowPptParser:
                     logging.exception(e)
             txts.append("\n".join(texts))
 
-        return txts
\ No newline at end of file
+        return txts