diff --git a/lib/flake-helper.nix b/lib/flake-helper.nix
index 1e3acaa..3fd2d33 100644
--- a/lib/flake-helper.nix
+++ b/lib/flake-helper.nix
@@ -40,5 +40,5 @@ rec {
 
   mapToColmenaHosts = hosts: builtins.mapAttrs (generateColmenaHost) hosts;
 
-  buildHosts = hosts: builtins.mapAttrs (name: host: host.config.system.build.toplevel) hosts;
+  buildHosts = hosts: builtins.mapAttrs (name: host: host.config.system.build.toplevel) (nixpkgs.lib.filterAttrs (name: host: (builtins.substring 0 1 name) != "_") hosts);
 }