Carstens et al. (2009) presented a method for evaluating models of historical demography under the isolation-with-migration model implemented in the software package IMa (Hey & Nielsen 2007). Our manuscript suggested that phylogeographic inferences could be made with a demographic model-selection framework using AIC scores of the models and information theoretic statistics (Burnham & Anderson 1998). Regretfully, we made a mistake in the calculation of the −ln L values reported in Table 3 (Carstens et al. 2009). This mistake resulted from a misinterpretation of the IMa output; it is not possible to calculate the likelihood of the reduced models using IMa. However, we are still able to compare the relative AIC differences among models using the −log(P) values, which are the maximized posterior density functions of each of the models considered by IMa given the data. Their usage in the calculation of information theory metrics such as the AIC differences (Δi) follows from the justification provided by Hey & Nielsen (2007), who used these values to conduct likelihood ratio tests. While the absolute AIC values (reported in Table 4) are affected by the erroneous calculation of the likelihoods of the reduced models, the relative differences among AIC values do not change when the −log(P) values are used to calculate AIC scores. Consequently, neither the biological inferences regarding the evolution of Pseudofagus idahoensis, or the general approach to phylogeography suggested by Carstens et al. (2009) are compromised.