diff --git a/installer/data/mysql/kohastructure.sql b/installer/data/mysql/kohastructure.sql
index 3a305856e4..12b7924ce3 100644
--- a/installer/data/mysql/kohastructure.sql
+++ b/installer/data/mysql/kohastructure.sql
@@ -1148,6 +1148,7 @@ CREATE TABLE `issues` ( -- information related to check outs or issues
   `issuedate` datetime default NULL, -- date the item was checked out or issued
   `onsite_checkout` int(1) NOT NULL default 0, -- in house use flag
   PRIMARY KEY (`issue_id`),
+  UNIQUE KEY `itemnumber` (`itemnumber`),
   KEY `issuesborridx` (`borrowernumber`),
   KEY `itemnumber_idx` (`itemnumber`),
   KEY `branchcode_idx` (`branchcode`),
diff --git a/installer/data/mysql/updatedatabase.pl b/installer/data/mysql/updatedatabase.pl
index 3b2bc55484..99c126d2bf 100755
--- a/installer/data/mysql/updatedatabase.pl
+++ b/installer/data/mysql/updatedatabase.pl
@@ -11247,6 +11247,16 @@ if(CheckVersion($DBversion)) {
     SetVersion($DBversion);
 }
 
+$DBversion = 'XXX';
+if ( CheckVersion($DBversion) ) {
+    my $create_table_issues = @{ $dbh->selectall_arrayref(q|SHOW CREATE TABLE issues|) }[0]->[1];
+    if ($create_table_issues !~ m|UNIQUE KEY.*itemnumber| ) {
+        $dbh->do(q|ALTER TABLE issues ADD CONSTRAINT UNIQUE KEY (itemnumber)|);
+    }
+    print "Update to $DBversion done (Bug 14978: Make sure issues.itemnumber is a unique key)\n";
+    SetVersion($DBversion);
+}
+
 # DEVELOPER PROCESS, search for anything to execute in the db_update directory
 # SEE bug 13068
 # if there is anything in the atomicupdate, read and execute it.