diff --git a/installer/data/mysql/atomicupdate/bug20754.perl b/installer/data/mysql/atomicupdate/bug20754.perl
new file mode 100644
index 0000000000..b819674141
--- /dev/null
+++ b/installer/data/mysql/atomicupdate/bug20754.perl
@@ -0,0 +1,11 @@
+$DBversion = 'XXX';  # will be replaced by the RM
+if( CheckVersion( $DBversion ) ) {
+    # From: https://stackoverflow.com/questions/3311903/remove-duplicate-rows-in-mysql
+    $dbh->do(q|
+DELETE a
+FROM virtualshelfshares as a, virtualshelfshares as b
+WHERE a.id < b.id AND a.borrowernumber IS NOT NULL AND a.borrowernumber=b.borrowernumber AND a.shelfnumber=b.shelfnumber
+    |);
+    SetVersion( $DBversion );
+    print "Upgrade to $DBversion done (Bug 20754: Remove double accepted list shares)\n";
+}