  We consider $\alpha'$ corrections to the one-loop four-point correlator of
the stress-tensor multiplet in $\mathcal{N}=4$ super Yang-Mills at order
$1/N^4$. Holographically, this is dual to string corrections of the one-loop
supergravity amplitude on AdS$_5\times$S$^5$. While this correlator has been
considered in Mellin space before, we derive the corresponding position space
results, gaining new insights into the analytic structure of AdS
loop-amplitudes. Most notably, the presence of a transcendental weight three
function involving new singularities is required, which has not appeared in the
context of AdS amplitudes before. We thereby confirm the structure of string
corrected one-loop Mellin amplitudes, and also provide new explicit results at
orders in $\alpha'$ not considered before.
