Both Real Madrid and Atletico Madrid have lost their appeals against FIFA bans on signing players in the next two transfer windows.
The Spanish clubs had decided to appeal the penalties placed upon them by the world governing body, having breached rules regarding the transfer of non-Spanish players under the age of 18.
The transfer bans were originally imposed by FIFA's Disciplinary Committee earlier in January, but were temporarily lifted once the clubs lodged their appeals, meaning that both were still able to sign players in the summer transfer window.
"The FIFA Appeal Committee has decided to reject the appeals lodged by Spanish clubs Atletico de Madrid and Real Madrid and to confirm in their entirety the decisions rendered by the FIFA Disciplinary Committee in the respective cases relating to the protection of minors," FIFA said in a statement on Thursday.
The decision by FIFA's Appeal Committee means that both clubs will now have to wait until January 2018 to make any new signings.