We found an error in (2.4) of Ledda et al. (Reference Ledda, Balestra, Lerisson, Scheid, Wyart and Gallaire2021). The correct non-dimensional expression for the curvature of the free surface is
\[ \kappa=\boldsymbol{\nabla } \boldsymbol{\cdot} \left(\frac{\nabla(h+h^0)}{\sqrt{1+\left(\dfrac{h_N}{l_c^*}\right)^2\vert\nabla(h+h^0)\vert^2}}\right). \]
While this error does not bear any consequence in the linear analysis at the core of this paper, the value 
$h_{N}/l_{c}^{*}=1$ has to be specified in figures 15, 16, 17, 21, without altering the discussion.
Funding
We acknowledge the Swiss National Science Foundation under grant 200021_178971.
Declaration of interests
The authors report no conflict of interest.
