Internal friction investigations are made of point defect‐dislocation interactions in silver bromide single crystals doped with small concentrations of either divalent cadmium, a prototype “normal” solute, or divalent strontium, which exhibits very strong segregation to dislocations. For AgBr:Cd2+, the results are unexceptional: the temperature dependence of the internal friction parameters gives a solute‐dislocation binding energy of about 0.15 eV, and the recovery of the strain amplitude‐independent decrement, after perturbation by high‐amplitude oscillatory stress, proceeds as predicted for the redistribution of the solute from the crystal bulk. In contrast, the results for the AgBr:Sr2+ are anomalous: the apparent solute‐dislocation binding energies are very sensitive to the dopant concentration and to the thermal history of the specimens, and the recovery of the decrement after excitation by high‐amplitude oscillatory stress shows several unusual features. All of the results can be qualitatively interpreted with a model in which the strontium pins have a great probability of migrating along the dislocation, without dissociating from it. Thus, an applied stress produces changes in both the complexity of the solute aggregates and also their distribution in the crystal. It is striking that strong evidence is found for the presence of such aggregates even for Sr2+ concentrations as low as a few parts per million.