diff --git a/Koha/Schema/Result/Issue.pm b/Koha/Schema/Result/Issue.pm
index 0a0eb17124..0144a86a63 100644
--- a/Koha/Schema/Result/Issue.pm
+++ b/Koha/Schema/Result/Issue.pm
@@ -165,6 +165,20 @@ __PACKAGE__->add_columns(
 
 __PACKAGE__->set_primary_key("issue_id");
 
+=head1 UNIQUE CONSTRAINTS
+
+=head2 C<itemnumber>
+
+=over 4
+
+=item * L</itemnumber>
+
+=back
+
+=cut
+
+__PACKAGE__->add_unique_constraint("itemnumber", ["itemnumber"]);
+
 =head1 RELATIONS
 
 =head2 borrowernumber
@@ -208,8 +222,8 @@ __PACKAGE__->belongs_to(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.07039 @ 2015-04-23 13:04:51
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:3JH0+3CuwwhPyebyt/z+uw
+# Created by DBIx::Class::Schema::Loader v0.07039 @ 2015-11-04 12:00:58
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:kREecsHr6wZPiokS946BHw
 
 __PACKAGE__->belongs_to(
     "borrower",
diff --git a/Koha/Schema/Result/Item.pm b/Koha/Schema/Result/Item.pm
index c342f46adb..08031b2c31 100644
--- a/Koha/Schema/Result/Item.pm
+++ b/Koha/Schema/Result/Item.pm
@@ -540,16 +540,16 @@ __PACKAGE__->belongs_to(
   },
 );
 
-=head2 issues
+=head2 issue
 
-Type: has_many
+Type: might_have
 
 Related object: L<Koha::Schema::Result::Issue>
 
 =cut
 
-__PACKAGE__->has_many(
-  "issues",
+__PACKAGE__->might_have(
+  "issue",
   "Koha::Schema::Result::Issue",
   { "foreign.itemnumber" => "self.itemnumber" },
   { cascade_copy => 0, cascade_delete => 0 },
@@ -616,8 +616,8 @@ __PACKAGE__->might_have(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.07039 @ 2015-04-23 12:42:12
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:urSpNt7LBda4T5Plhi6cPw
+# Created by DBIx::Class::Schema::Loader v0.07039 @ 2015-11-04 12:00:58
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:jkgJfulDrGaUpQ6jC40vpQ
 
 sub effective_itemtype {
     my ( $self ) = @_;