diff --git a/api/core/workflow/nodes/document_extractor/node.py b/api/core/workflow/nodes/document_extractor/node.py
index e2faae2f4d..4f3bfdf24e 100644
--- a/api/core/workflow/nodes/document_extractor/node.py
+++ b/api/core/workflow/nodes/document_extractor/node.py
@@ -11,7 +11,7 @@ import docx
 import pandas as pd
 import pypandoc  # type: ignore
 import pypdfium2  # type: ignore
-import webvtt
+import webvtt # type: ignore
 import yaml  # type: ignore
 from docx.document import Document
 from docx.oxml.table import CT_Tbl
@@ -468,6 +468,7 @@ def _extract_text_from_msg(file_content: bytes) -> str:
     except Exception as e:
         raise TextExtractionError(f"Failed to extract text from MSG: {str(e)}") from e
 
+
 def _extract_text_from_vtt(vtt_bytes: bytes) -> str:
     text = _extract_text_from_plain_text(vtt_bytes)