diff --git a/krebs/3modules/exim-smarthost.nix b/krebs/3modules/exim-smarthost.nix
index 7a5a55d49..62f15027a 100644
--- a/krebs/3modules/exim-smarthost.nix
+++ b/krebs/3modules/exim-smarthost.nix
@@ -55,6 +55,7 @@ let
           };
         };
       }));
+      default = [];
     };
 
     local_domains = mkOption {
@@ -109,6 +110,7 @@ let
           };
         };
       }));
+      default = [];
     };
   };