diff --git a/se/se_epub_generate_toc.py b/se/se_epub_generate_toc.py
index d1b10763..11d1ce8e 100644
--- a/se/se_epub_generate_toc.py
+++ b/se/se_epub_generate_toc.py
@@ -474,7 +474,7 @@ def get_toc_id_for_special_item(node: EasyXmlElement) -> str:
 		toc_id = parent.get_attr("id")
 		if toc_id:
 			return toc_id
-	return None
+	return ""
 		
 
 def get_level(node: EasyXmlElement, toc_list: list) -> int: