diff --git a/components/fpspreadsheet/source/crypto/xlsxooxml_crypto.pas b/components/fpspreadsheet/source/crypto/xlsxooxml_crypto.pas
index 977a59324..329129bfd 100644
--- a/components/fpspreadsheet/source/crypto/xlsxooxml_crypto.pas
+++ b/components/fpspreadsheet/source/crypto/xlsxooxml_crypto.pas
@@ -1,5 +1,7 @@
 unit xlsxooxml_crypto;
 
+{$mode objfpc}{$H+}
+
 interface
 
 uses