diff --git a/src/html_epub_preprocessor.py b/src/html_epub_preprocessor.py
index 10714cf..265ae61 100644
--- a/src/html_epub_preprocessor.py
+++ b/src/html_epub_preprocessor.py
@@ -302,6 +302,11 @@ def unwrap_structural_tags(body_tag):
         'figure', 'footer', 'iframe', 'span', 'p'
     ]
 
+    # comments removal
+    for tag in body_tag.find_all():
+        for element in tag(text=lambda text: isinstance(text, Comment)):
+            element.extract()
+
     for div in body_tag.find_all("div"):
         if div.attrs.get('class'):
             div_class = div.attrs['class'] if not isinstance(div.attrs['class'], list) else div.attrs['class'][0]
@@ -500,7 +505,7 @@ def preprocess_pre_tags(chapter_tag):
 
         for child in pre.children:
             if isinstance(child, NavigableString):
-                cleaned_text = _prepare_formatted(pre.text)
+                cleaned_text = _prepare_formatted(str(child))
                 sub_strings = re.split('\r\n|\n|\r', cleaned_text)
                 for string in sub_strings:
                     new_tag.append(NavigableString(string))
@@ -519,8 +524,7 @@ def preprocess_pre_tags(chapter_tag):
 
         new_tag.attrs['style'] = "font-family: courier new,courier,monospace; " \
                                  "font-size: 14px; white-space: nowrap;"
-        pre.insert_before(new_tag)
-        pre.extract()
+        pre.replace_with(new_tag)
         table = wrap_preformatted_span_with_table(chapter_tag, new_tag)
         p_for_br = chapter_tag.new_tag("p")
         p_for_br.string = "\xa0"
@@ -570,10 +574,6 @@ def prepare_title_and_content(title, chapter_tag: BeautifulSoup, remove_title_fr
         if hasattr(tag, 'attrs') and tag.attrs.get('class') and (tag.attrs.get('class') not in ['link-anchor',
                                                                                                 'footnote-element']):
             del tag.attrs['class']
-    # 3. comments removal
-    for tag in chapter_tag.find_all():
-        for element in tag(text=lambda text: isinstance(text, Comment)):
-            element.extract()
     # content_str = re.sub(r'([\n\t\xa0])', ' ', str(content_tag))
     title_str = clean_title_from_numbering(title_str)
     return title_str, str(chapter_tag)