diff --git a/Koha/Edifact/Order.pm b/Koha/Edifact/Order.pm
index ac63a94a9a..dcab51dede 100644
--- a/Koha/Edifact/Order.pm
+++ b/Koha/Edifact/Order.pm
@@ -596,7 +596,7 @@ sub additional_product_id {
         $product_id   = $1;
         $product_code = 'EN';
     }
-    elsif ( $isbn_field =~ m/(\d{9})[Xx\d]/ ) {
+    elsif ( $isbn_field =~ m/(\d{9}[Xx\d])/ ) {
         $product_id   = $1;
         $product_code = 'IB';
     }