diff --git a/src/html_epub_preprocessor.py b/src/html_epub_preprocessor.py
index 85d5900..06878de 100644
--- a/src/html_epub_preprocessor.py
+++ b/src/html_epub_preprocessor.py
@@ -382,7 +382,7 @@ def get_tags_between_chapter_marks(first_id, href, html_soup):
     return tags
 
 
-def wrap_text_with_table(main_tag, text, old_tag):
+def wrap_span_with_table(main_tag, old_tag):
     table = main_tag.new_tag("table")
     table.attrs['border'] = '0'
     table.attrs['style'] = 'width:100%;'
@@ -391,8 +391,7 @@ def wrap_text_with_table(main_tag, text, old_tag):
     td = main_tag.new_tag("td")
     td.attrs['style'] = 'font-family: courier new,courier,monospace;'
     td.attrs['bgcolor'] = '#f5f5f5'
-    td.insert(0, str(text))
-    old_tag.replace_with(td)
+    old_tag.wrap(td)
     td.wrap(tr)
     tr.wrap(tbody)
     tbody.wrap(table)
@@ -401,20 +400,17 @@ def wrap_text_with_table(main_tag, text, old_tag):
 
 def preprocess_pre_tags(chapter_tag):
     for pre in chapter_tag.find_all("pre"):
-        if not pre.children:
-            assert 1, 'Pre tag has other tags.'
-        else:
-            wrap_text_with_table(chapter_tag, escape(pre.text), pre)
+        for child in pre.children:
+            if isinstance(child, NavigableString):
+                child.text = escape(pre.text)
+        pre.name = 'span'
+        wrap_span_with_table(chapter_tag, pre)
 
 
 def preprocess_code_tags(chapter_tag):
     for code in chapter_tag.find_all("code"):
-        if not code.children:
-            assert 1, 'Code tag has other tags.'
-        else:
-            code.string = escape(code.text)
-            code.name = 'span'
-            code.attrs['style'] = 'color:#c7254e; font-family: courier new,courier,monospace;'
+        code.name = 'span'
+        code.attrs['style'] = 'color:#c7254e; font-family: courier new,courier,monospace;'
 
 
 def prepare_title_and_content(title, chapter_tag: BeautifulSoup, remove_title_from_chapter) -> Tuple[str, str]:
@@ -435,8 +431,8 @@ def prepare_title_and_content(title, chapter_tag: BeautifulSoup, remove_title_fr
         clean_headings_content(chapter_tag, title_str)
     _process_lists(chapter_tag)
     preprocess_table(chapter_tag)
-    preprocess_pre_tags(chapter_tag)
     preprocess_code_tags(chapter_tag)
+    preprocess_pre_tags(chapter_tag)
     # 2. class removal
     for tag in chapter_tag.find_all(recursive=True):
         if hasattr(tag, 'attrs') and tag.attrs.get('class') and (tag.attrs.get('class') not in ['link-anchor']):