diff --git a/scripts/invoices/email_unpaid_invoices_to_customers.php b/scripts/invoices/email_unpaid_invoices_to_customers.php
index f616ac837ef..c92a51d85db 100755
--- a/scripts/invoices/email_unpaid_invoices_to_customers.php
+++ b/scripts/invoices/email_unpaid_invoices_to_customers.php
@@ -176,7 +176,7 @@ function envoi_mail($mode,$oldemail,$message,$total,$userlang,$oldcustomer)
     $sendto = $oldemail;
     $from = $conf->global->MAIN_MAIL_EMAIL_FROM;
     $errorsto = $conf->global->MAIN_MAIL_ERRORS_TO;
-	$msgishtml = 0;
+	$msgishtml = -1;
 
     print "- Send email for ".$oldcustomer."(".$oldemail."), total: ".$total."\n";
     dol_syslog("email_unpaid_invoices_to_customers.php: send mail to ".$oldemail);
diff --git a/scripts/invoices/email_unpaid_invoices_to_representatives.php b/scripts/invoices/email_unpaid_invoices_to_representatives.php
index 3f4eac8e819..6b050ec7f71 100755
--- a/scripts/invoices/email_unpaid_invoices_to_representatives.php
+++ b/scripts/invoices/email_unpaid_invoices_to_representatives.php
@@ -179,7 +179,7 @@ function envoi_mail($mode,$oldemail,$message,$total,$userlang,$oldsalerepresenta
     $sendto = $oldemail;
     $from = $conf->global->MAIN_MAIL_EMAIL_FROM;
     $errorsto = $conf->global->MAIN_MAIL_ERRORS_TO;
-	$msgishtml = 0;
+	$msgishtml = -1;
 
     print "- Send email for ".$oldsalerepresentative." (".$oldemail."), total: ".$total."\n";
     dol_syslog("email_unpaid_invoices_to_representatives.php: send mail to ".$oldemail);