Elliptic flow of heavy-flavour decay electrons at mid-rapidity ($|y|$ $< $ 0.7) (closed symbols) as a function of $p_{\rm T}$ compared to the elliptic flow of heavy-flavour decay muons at forward rapidity (2.5 $< $ $y$ $< $ 4) (open symbols) in the 0-10% (left panel), 10-20% (middle panel) and 20-40% (right panel) centrality classes in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV. The symbols are placed at the centre of the $p_{\rm T}$ interval whose width is shown by the horizontal error bar. The vertical error bars and open boxes represent the statistical and systematic uncertainties, respectively.