diff --git a/clanModules/zerotier/shared.nix b/clanModules/zerotier/shared.nix
index cb4dc3492..72e8ccca8 100644
--- a/clanModules/zerotier/shared.nix
+++ b/clanModules/zerotier/shared.nix
@@ -53,6 +53,10 @@ in
         assertion = builtins.length roles.controller.machines == 1;
         message = "The zerotier module requires exactly one controller, but found ${builtins.toString roles.controller.machines}";
       }
+      {
+        assertion = builtins.length roles.moons.machines <= 7;
+        message = "The zerotier module allows at most for seven moons , but found ${builtins.toString roles.moons.machines}";
+      }
     ];
 
     clan.core.networking.zerotier.networkId = networkId;