diff --git a/javascripts/discourse/components/spreadsheet-editor.js b/javascripts/discourse/components/spreadsheet-editor.js
index 123fa2a..57750ab 100644
--- a/javascripts/discourse/components/spreadsheet-editor.js
+++ b/javascripts/discourse/components/spreadsheet-editor.js
@@ -193,6 +193,8 @@ export default class SpreadsheetEditor extends Component {
       editedTable = raw.replace(findTableRegex(), newRaw);
     }
 
+    // replace null characters
+    editedTable = editedTable.replace(/\0/g, "\ufffd");
     return editedTable;
   }