Healthcare company Novartis said an upgrade at one of its manufacturing facilities is behind shortages of over-the-counter medications that ease cold and flu symptoms.

Buckley’s, NeoCitran, Otrivin and Triaminic are in short supply in Canada.

Novartis said it is upgrading its Nebraska facility.

The U.S Food and Drug Administration reportedly cited Novartis’ plant for at least a dozen quality control problems last year.