Improving channel relationships is critical for marketers aiming to strategically manage and motivate their distribution partners. In this study, we explore distributor voice as an extra-role behavior and its influence on channel relationship quality. We propose that this behavior has a curvilinear effect on channel relationship quality, and such effect is conditional on channel interdependence and the presence of an opportunistic atmosphere between channel members. From a sample of 191 distributors in China, we find that distributor voice has an inverted U-shaped effect on channel relationship quality. This effect becomes stronger with high levels of channel interdependence or low levels of opportunism between distributors and suppliers. We also discuss the theoretical and practical implications of our findings.