diff --git a/src/epub_converter/epub_converter.py b/src/epub_converter/epub_converter.py
index 9eec34e..6e83e74 100644
--- a/src/epub_converter/epub_converter.py
+++ b/src/epub_converter/epub_converter.py
@@ -99,7 +99,7 @@ class EpubConverter:
         self.process_internal_links()
         self.book_logger.log(
             f"Check if converter-chapter-marks are on the same level.")
-        self.chapter_marks_are_same_level()
+        self.chapter_marks_are_first_level()
         self.book_logger.log(f"Define chapters content.")
         self.define_chapters_with_content()
         self.book_logger.log(f"Converting html_nodes to LiveCarta chapter items.")
@@ -276,23 +276,23 @@ class EpubConverter:
             self.hrefs_added_to_toc.add(file)
 
     def label_subchapters_with_lc_tag(self):
-        for html_href in self.html_href2html_body_soup:
-            ids, soup = self.html_href2subchapters_ids[html_href], \
-                self.html_href2html_body_soup[html_href]
-            for i in ids:
+        for html_href, soup in self.html_href2html_body_soup.items():
+            for i in self.html_href2subchapters_ids[html_href]:
                 tag = soup.find(id=i)
+                # in order not to lose tags in verification of same level of chapter
+                parent_tag = tag.find_parents(['p', 'span', 'div', 'h1', 'h2', 'h3', 'h4', 'h5'])[-1]
                 tmp_tag = soup.new_tag("lc_tmp")
                 tmp_tag.attrs["class"] = "converter-chapter-mark"
                 tmp_tag.attrs["id"] = i
-                tag.insert_before(tmp_tag)
+                parent_tag.insert_before(tmp_tag)
 
-    def chapter_marks_are_same_level(self):
+    def chapter_marks_are_first_level(self):
         """
-        Function checks that marks for pointing a start of a chapter are placed on one level in html tree.
+        Function checks that marks for pointing a start of a chapter are placed on 1st level in html tree.
         Mark is tag with "class": "converter-chapter-mark". Added while TOC was parsed.
         This tag must have a chapter_tag as a parent.
-        Otherwise, it is wrapped with some tags. Like:
-        <p> <span id="123", class="converter-chapter-mark"> </span> </p>
+        Otherwise, it's wrapped with some tags. Like:
+        <p> <lc_tmp id="123", class="converter-chapter-mark"> </lc_tmp> </p>
 
         """
         for html_href in self.html_href2html_body_soup:
@@ -304,7 +304,7 @@ class EpubConverter:
             # fix marks to be on 1 level
             for mark in marks:
                 while mark.parent != chapter_tag:
-                    # todo warning! could reflect on formatting/internal links in some cases
+                    # todo warning! could reflect on formatting/internal links in some cases (it removes tags using unwrap)
                     mark.parent.unwrap()
 
     @staticmethod