Vesicle trafficking is essential for many developmental events in Drosophila, such as eye and bristle development and synaptic morphogenesis. On p. 4655, Khodosh and colleagues provide new information about the developmental regulation of this process by reporting that the Drosophila BEACH protein Blue cheese (Bchs) antagonizes Rab11, a small GTPase that is involved in vesicle trafficking. BEACH proteins (large proteins that contain a `Beige and Chédiak-Higashi domain') have been implicated in membrane trafficking, but how they regulate this process is a mystery. The researchers show that reductions in bchs function suppress the effects of loss-of-function rab11 mutations in bristle and eye development; they also suppress the changes in synapse morphology at the neuromuscular junction (NMJ) that are caused by reductions in rab11 function. Consistent with this last effect, Bchs colocalizes with Rab11 at the NMJ in vesicles. The researchers conclude that Bchs antagonizes Rab11 during development and suggest that interactions between other BEACH proteins and small GTPases could also regulate vesicle trafficking during development.