  We discuss the quantum correction to chaos in the Schwarzian theory. We carry
out the semi-classical analysis of the Schwarzian theory to study Feynman
diagrams of the Schwarzian soft mode. We evaluate the contribution of the soft
mode to the out-of-time-order correlator up to order $\mathcal{O}(g^4)$. We
show that the quantum correction of order $\mathcal{O}(g^4)$ by the soft mode
decreases the maximum Lyapunov exponent $2\pi/ \beta$.
