The Luxembourg Companies Act of 10 August 1915, as amended inter alia by the Act of 10 August 2016 (the "Act"), introduces several new grounds to invalidate shareholder decisions. In this regard, a distinction should be made between grounds generally applicable to shareholder decisions in all types of companies and those applicable to a particular type of corporate form, such as an S.A. (société anonyme), S.C.A. (société en commandite par actions), S.À R.L. (société à responsabilité limitée) and/or S.A.S. (société par actions simplifiée). The new rules provide useful clarification and greater legal certainty for shareholders.