diff --git a/nix/hm-module.nix b/nix/hm-module.nix
index 4e6ed0b..89c884e 100644
--- a/nix/hm-module.nix
+++ b/nix/hm-module.nix
@@ -44,6 +44,7 @@ in {
           };
         };
       });
+      default = [];
     };
 
     lockCmd = mkOption {