diff --git a/addons/account_greek_fiscal/account_invoice_report.xml b/addons/account_greek_fiscal/account_invoice_report.xml
index 894d21a730d..c1032521499 100644
--- a/addons/account_greek_fiscal/account_invoice_report.xml
+++ b/addons/account_greek_fiscal/account_invoice_report.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <openerp>
 	<data>
-	        <report auto="False" id="account_fiscalgr_invoices_report" model="account.invoice" report_type="txt" name="account.invoice.fiscalgr" rml="account_greek_fiscal/report/invoice.rml" string="Fiscal Invoice" attachment="print-"/>
+	        <report auto="False" id="account_fiscalgr_invoices_report" model="account.invoice" report_type="txt" name="account.invoice.fiscalgr" rml="account_greek_fiscal/report/invoice.rml" string="Fiscal Invoice" attachment="'print-'"/>
 		<!-- default properties -->
 		<record model="ir.property" id="property_fiscalgr_invoice_report_out">
 			<field name="name">property_fiscalgr_invoice_report</field>