  The strong cosmic censorship conjecture (SCCC) proposed by Penrose states
that the presence of the inner Cauchy horizon ($\mathcal{CH}$) in the black
hole solutions does not threaten the deterministic nature of general relativity
since it is actually unstable against the remnant perturbation fields that fall
into the black hole. Although this conjecture is well-established for the
asymptotically flat spacetimes in general relativity, it is challenged upon
taking a small positive cosmological constant as required by observational
data. This challenge can be fixed by finding even one type of quasi-normal mode
whose decay rate is slow enough insofar as the remnant of perturbation is able
to destroy the $\mathcal{CH}$. By aiming to investigate the role of the
additional parameter induced by modified gravity in this scenario, we consider
the charged-de Sitter black hole solutions of Einstein-Maxwell theory extended
with $f(R)$ and Energy-Momentum Squared Gravities. Employing the numerical
analysis of the deterministic criterion, we show that the presence of the model
parameter of theories at hand within a given range controls the decay rate of
the photon sphere quasi-normal modes (in the eikonal limit) to rescue SCCC.
