diff --git a/fediversity/default.nix b/fediversity/default.nix
index 3f39485b..9c60d61d 100644
--- a/fediversity/default.nix
+++ b/fediversity/default.nix
@@ -22,7 +22,7 @@ in {
       };
 
       domain = mkOption {
-        type = types.string;
+        type = types.str;
       };
 
       mastodon.enable = mkEnableOption "default Fediversity Mastodon configuration";