The temperature-dependent flow behavior in nominally binary Al-Mg alloys measured recently (Jobba etal., 2015; Niewczas et al., 2015) is interpreted in the context of a parameter-free solute strengthening model. The recent measurements show consistently higher strengths as compared to literature data on true binary Al-Mg alloys, which is attributed to the presence of Fe in the nominally binary Al-Mg. Using the Fe concentration as a single fitting parameter, the model predictions for the newer materials when treated as Al-Mg-(Fe) alloys agree with experiments to the same degree as obtained for the true binary Al-Mg. The model then predicts the activation volume in good agreement with experimental trends. (c) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.