The present disclosure relate to a method performed by a UE (102) for handling an invalid SI signature in a communication system. The UE obtains SI and an associated SI signature for a cell. The UE (102) determines if the obtained SI signature is valid or invalid. If the signature is valid, the UE (102) determines to use the cell. If the SI signature is invalid, the UE (102) determines if the UE (102) is configured to bar cells or not. If the SI signature is invalid and if the UE (102) is not configured to bar cells with invalid SI signature, the UE (102) determines to use the cell. If the SI signature is invalid and the UE (102) is configured to bar cells with invalid SI signature, the UE (102) determines to bar the cell and select another cell to use.