Both archaeologists and the wider public require certainty as to how archaeological heritage law is to be interpreted. In this contribution, I prove that the interpretation of § 11 (1) Austrian Monuments Protection Law (DMSG) currently applied by the Austrian National Heritage Agency (BDA) must be illegal, since it would seriously breach the Austrian constitution, especially Art. 17 Staatsgrundgesetz (StGG). It is argued that there is only one other possible and legal interpretation of the provisions of § 11 (1) DMSG. It is recommended the BDA immediately chances its policy and practice to avoid becoming liable to massive damages.