The move towards simplified models for Run II of the LHC will allow for stronger and more robust constraints on the dark sector. However there already exists a wealth of Run I data which should not be ignored in the run-up to Run II. Here we reinterpret public constraints on generic beyond-standard-model cross sections to place new constraints on a simplified model. We make use of an ATLAS search in the monojet + missing energy channel to constrain a representative simplified model with the dark matter coupling to an axial-vector Z ′ . We scan the entire parameter space of our chosen model to set the strongest current collider constraints on our model using the full 20.3 fb −1 ATLAS 8 TeV dataset and provide predictions for constraints that can be set with 20 fb −1 of 14 TeV data. Our technique can also be used for the interpretation of Run II data and provides a broad benchmark for comparing future constraints on simplified models.