diff --git a/krebs/3modules/default.nix b/krebs/3modules/default.nix
index a8933e719..7cf02cd8b 100644
--- a/krebs/3modules/default.nix
+++ b/krebs/3modules/default.nix
@@ -61,6 +61,7 @@ let
 
     hosts = mkOption {
       type = with types; attrsOf host;
+      default = {};
     };
 
     users = mkOption {