The European LCS and CS will ban Challenger sister teams entirely beginning with the 2017 EU LCS and CS Summer Split, Riot announced Tuesday.

Among a list of changes to the EU CS and Promotion tournament format Riot published on Tuesday, the organization confirmed that their sister team policy is becoming more severe than was previously thought.

In December, then-Riot Games senior esports coordinator J.T. Vandenbree tweeted that NA LCS teams with NA CS sister teams would be unable to participate in the Promotion Tournament, to remove the incentive to build a farm team.

In Europe, Riot has stated that organizations will not be allowed to have sister teams at all — only one team in either the EU LCS or CS, not both. A spokesperson for Riot Games confirmed that the change will not be coming to North America, and NA organizations will still be able to field teams in both Challenger and LCS throughout 2017.

Other changes to Europe include only sending two teams down to the Promotion Tournament, the ten-ban format coming to CS and playoffs changing to two best-of-five matches between the Top 4 CS teams to determine who qualifies for promotion.

The EU CS will run from Feb. 5 to March 26.

Clarification: A previous version of this story did not specify that Vandenbree's statements in December were specifically regarding the NA LCS and CS.

Daniel Rosen is a news editor for theScore esports. You can follow him on Twitter.