If Supersymmetry is to stabilise the Higgs boson mass, naturalness arguments suggest the mass of the scalar partner of the top quark (the stop) to be below around 1 TeV. The decay of the stop depends in part on the mass difference $\Delta m = m_{\tilde{t}}-m_{\tilde{\chi}^0_1}$ between the stop and the lightest neutralino, assumed to be stable. For $\Delta m < m_W + m_b$ the process $\tilde{t}\rightarrow c+\tilde{\chi}^0_1$ may dominate. This contribution presents a summary of stop searches targeting this region of parameter space. Conducted using a newly developed tagger for the identification of charm quarks, and using 36.5 fb$^{-1}$ of proton-proton collisions collected by the ATLAS detector at a centre-of-mass energy of $\sqrt{s}=13$ TeV, these searches significantly extend the exclusion limits in the $(m_{\tilde{\chi}^0_1}, m_{\tilde{t}})$ parameter space made by ATLAS during Run 1 of the LHC.