  In this work we study how the small contribution of the inner crust to the
total equation of state (EoS) of a neutron star affects its mass-radius
relation, focusing on the canonical mass of 1.4$M_\odot$. We build empirical
EoS of the kind - $p = K\epsilon^{\gamma} + b$ - in the range of 0.003
fm$^{-3}~<~n~<~$0.08 fm$^{-3}$ and also calculate the speed of sound in this
region. We see that different behaviours of the speed of sound can affect the
radius of the canonical star by more than 1.1 km. This result can help us
understand extreme results as GW170817, where some studies indicate that the
radius of the canonical star cannot exceed 11.9 km.
