diff --git a/src/epub_converter/html_epub_preprocessor.py b/src/epub_converter/html_epub_preprocessor.py
index 18f8902..e2fe136 100644
--- a/src/epub_converter/html_epub_preprocessor.py
+++ b/src/epub_converter/html_epub_preprocessor.py
@@ -126,7 +126,7 @@ def _remove_headings_content(content_tag, title_of_chapter: str):
     title_of_chapter = title_of_chapter.lower()
     for tag in content_tag.contents:
         text = tag if isinstance(tag, NavigableString) else tag.text
-        if re.sub(r'([\s\xa0])', '', text):
+        if re.sub(r"[\s\xa0]", "", text):
             text = re.sub(r"[\s\xa0]", " ", text).lower()
             text = text.strip() # delete extra spaces
             if title_of_chapter == text or \
@@ -134,9 +134,10 @@ def _remove_headings_content(content_tag, title_of_chapter: str):
                      re.findall(r"^h[1-3]$", tag.name or content_tag.name)):
                 _add_span_to_save_ids_for_links(tag, content_tag)
                 tag.extract()
+                return
             elif not isinstance(tag, NavigableString):
-                _remove_headings_content(tag, title_of_chapter)
-            break
+                if not _remove_headings_content(tag, title_of_chapter):
+                    break
 
 
 def _tags_to_correspond_livecarta_tag(chapter_tag):
@@ -275,13 +276,13 @@ def _preprocess_div_tags(chapter_tag):
     Function replace <div> with <table>:
     """
     for div in chapter_tag.find_all("div"):
-        if any(attr in ['width', 'border', 'bgcolor'] for attr in div.attrs):
+        if any(attr in ["width", "border", "bgcolor"] for attr in div.attrs):
             _wrap_tag_with_table(
                 chapter_tag,
                 tag_to_be_wrapped=div,
-                width=div.attrs['width'] if div.attrs.get('width') else '100',
-                border=div.attrs['border'] if div.attrs.get('border') else None,
-                bg_color=div.attrs['bgcolor'] if div.attrs.get('bgcolor') else None)
+                width=div.attrs["width"] if div.attrs.get("width") else "100",
+                border=div.attrs["border"] if div.attrs.get("border") else None,
+                bg_color=div.attrs["bgcolor"] if div.attrs.get("bgcolor") else None)
         else:
             div.name = "p"
             continue