diff --git a/src/wireviz/Harness.py b/src/wireviz/Harness.py
index 67d9e25..bcf0a38 100644
--- a/src/wireviz/Harness.py
+++ b/src/wireviz/Harness.py
@@ -321,7 +321,7 @@ class Harness:
             for row in listy[1:]:
                 file.write('<tr>')
                 for i, item in enumerate(row):
-                    item_str = item.replace('\u00b2', '<sup>2</sup>')
+                    item_str = item.replace('\u00b2', '&sup2;')
                     item_str = item_str.replace('\\n', '<br>')
                     align = 'align="right"' if listy[0][i] == 'Qty' else ''
                     file.write(f'<td {align} style="border:1px solid #000000; padding: 4px">{item_str}</td>')