diff --git a/nix/nixos-module/container/bird.nix b/nix/nixos-module/container/bird.nix
index 049ccc6..1ca74ef 100644
--- a/nix/nixos-module/container/bird.nix
+++ b/nix/nixos-module/container/bird.nix
@@ -40,7 +40,7 @@ in
 
           ${builtins.concatStringsSep "\n" (
             map (subnet6: ''
-              prefix ::/64 {
+              prefix ${subnet6} {
                 preferred lifetime 20;
                 valid lifetime 60;
               };