When judging how ‘fair’ voting rules are, a fundamental criterion used by both scholars and politicians is their ability or inability to produce proportional results, that is, the extent parties’ seat distribution after the elections accurately reflects their vote shares. How about citizens? Do citizens care about how proportional the outcome is? Or do they judge the outcome solely on the basis of how well (or poorly) their party performed? Taking advantage of a uniquely designed survey experiment, this paper investigates the causal effect of proportionality on voter support for voting rules in four countries, namely Austria, England, Ireland and Sweden. The results show that proportionality drives support for the voting rules not above but beyond party performance. There is little cross‐country variation, which suggests that proportionality is appreciated in different contexts with little status quo bias. These findings have important implications for our understanding of the causal mechanisms linking electoral rules to voter support.