  Angular correlations between heavy-flavour decay electrons and charged
particles at mid-rapidity ($|\eta| < 0.8$) are measured in p-Pb collisions at
$\sqrt{s_{\rm NN}}$ = 5.02 TeV. The analysis is carried out for the 0-20%
(high) and 60-100% (low) multiplicity ranges. The jet contribution in the
correlation distribution from high-multiplicity events is removed by
subtracting the distribution from low-multiplicity events. An azimuthal
modulation remains after removing the jet contribution, similar to previous
observations in two-particle angular correlation measurements for light-flavour
hadrons. A Fourier decomposition of the modulation results in a positive
second-order coefficient ($v_{2}$) for heavy-flavour decay electrons in the
transverse momentum interval $1.5 < p_{\rm{T}} < 4$ GeV/$c$ in
high-multiplicity events, with a significance larger than $5\sigma$. The
results are compared with those of charged particles at mid-rapidity and of
inclusive muons at forward rapidity. The $v_2$ measurement of open
heavy-flavour particles at mid-rapidity in small collision systems could
provide crucial information to help interpret the anisotropies observed in such
systems.
