We analyze the structure of gaugino interactions on D7-branes from a 10d perspective. This is essential if one wants to lift the standard 4d approach to type IIB moduli stabilization in 10d. Motivated by the structure of heterotic and Horava-Witten theories, we suggest an extension of the brane action by a particular four gaugino operator. In a simple toroidal compactification, we demonstrate that the 4d effective potential is exactly reproduced from 10d.