Former Wales captain Martyn Williams says the Pro12's top seven teams should qualify automatically for the European Champions Cup.
In the current system the best teams from Ireland, Wales, Scotland and Italy qualify, plus the next three highest placed teams in the league table.
Four Irish provinces have qualified for Europe's top flight this season, with only Scarlets from Wales.
But Zebre, who finished below Wales' three other teams, have made the cut.
Scottish team Edinburgh also finished above Zebre, but will be in the second-tier European Challenge Cup in 2016-17 with Ospreys missing out for the first time in their history.
"I think it's wrong," Williams told BBC Wales' Scrum V.
"It's the top seven in the league irrespective of what country you are from should get into the Champions Cup for the next season.
"With all due respect to Zebre they're not going to make any impact in the Champions Cup at all next season.
"If one team finishes seventh and the other one's 11th and they get in above you, that just doesn't seem right to me at all."
Cardiff Blues finished seventh and miss out and even Wales' lowliest team Newport Gwent Dragons finished above Zebre in the table.
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Zebre's final day victory over Dragons saw them pip Treviso to secure Champions Cup qualification.
As recently as the 2013-14 season, Wales was guaranteed three teams in the top flight with Blues, Scarlets and Ospreys playing in that season's competition.
In October 2013, the new qualification system was agreed with Ireland, Italy, Scotland and Wales all guaranteed one club in the Champions Cup with four other places for the Pro12 based purely on position in the final table.
In the first year under the new arrangement in 2014-15, Ospreys and Scarlets qualified, as they did for the current season.
But within three years of the new rules being introduced Wales will have only Scarlets in the tournament next season.