diff --git a/nixos/modules/services/web-servers/h2o/default.nix b/nixos/modules/services/web-servers/h2o/default.nix
index 7e021281f91a..896736f5c57a 100644
--- a/nixos/modules/services/web-servers/h2o/default.nix
+++ b/nixos/modules/services/web-servers/h2o/default.nix
@@ -138,6 +138,7 @@ in
 
       settings = mkOption {
         type = settingsFormat.type;
+        default = { };
         description = "Configuration for H2O (see <https://h2o.examp1e.net/configure.html>)";
       };