  We study the consistency of large-field inflation in low-energy effective
field theories of string theory. In particular, we focus on the stability of
K\"ahler moduli in the particularly interesting case where the non-perturbative
superpotential of the K\"ahler sector explicitly depends on the inflaton field.
This situation arises generically due to one-loop corrections to the instanton
action. The field dependence of the modulus potential feeds back into the
inflationary dynamics, potentially impairing slow roll. We distinguish between
world-sheet instantons from Euclidean D-branes, which typically yield
polynomial one-loop Pfaffians, and gaugino condensates, which can yield
exponential or periodic corrections. In all scenarios successful slow-roll
inflation imposes bounds on the magnitude of the one-loop correction,
corresponding to constraints on possible compactifications. While we put a
certain emphasis on Type IIB constructions with mobile D7-branes, our results
seem to apply more generally.
