diff --git a/docs/topics/reading-and-writing-to-file.md b/docs/topics/reading-and-writing-to-file.md
index 0bcc1909af..55929e85c6 100644
--- a/docs/topics/reading-and-writing-to-file.md
+++ b/docs/topics/reading-and-writing-to-file.md
@@ -282,6 +282,7 @@ versions of Microsoft Excel.
 **Excel 2003 XML limitations** Please note that Excel 2003 XML format
 has some limits regarding to styling cells and handling large
 spreadsheets via PHP.
+Also, only files using charset UTF-8 are supported.
 
 ### \PhpOffice\PhpSpreadsheet\Reader\Xml
 
@@ -701,6 +702,7 @@ extension.
 
 **HTML limitations** Please note that HTML file format has some limits
 regarding to styling cells, number formatting, ...
+Also, only files using charset UTF-8 are supported.
 
 ### \PhpOffice\PhpSpreadsheet\Reader\Html