diff --git a/CHANGELOG.md b/CHANGELOG.md
index c239358..3bea157 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,14 @@
 All notable changes to this project will be documented in this file. See [conventional commits](https://www.conventionalcommits.org/) for commit guidelines.
 
 - - -
+## [v0.2.1](https://gitlab.com/TECHNOFAB/soonix/compare/e508bfb4743b7c22897469640fe1a14969603a8b..v0.2.1) - 2026-10-07
+#### Bug Fixes
+- (**lib**) default `yaml` format to yaml_1_2 - ([3ae3055](https://gitlab.com/TECHNOFAB/soonix/commit/3ae305554683bdf252edf971c1404419479a778c)) - [@TECHNOFAB](https://gitlab.com/TECHNOFAB)
+#### Miscellaneous Chores
+- (**deps**) lock file maintenance - ([e508bfb](https://gitlab.com/TECHNOFAB/soonix/commit/e508bfb4743b7c22897469640fe1a14969603a8b)) - Renovate Bot
+
+- - -
+
 ## [v0.2.0](https://gitlab.com/TECHNOFAB/soonix/compare/a8acaf7143572dac1bc02b124e593d68b5bdddc7..v0.2.0) - 2026-01-28
 #### Features
 - (**generator**) add Mustache - ([26e79ed](https://gitlab.com/TECHNOFAB/soonix/commit/26e79ede19e815a619a3878ffd5fa6b757da50c4)) - asimon
diff --git a/lib/lib.nix b/lib/lib.nix
index 3e6005d..e9875c0 100644
--- a/lib/lib.nix
+++ b/lib/lib.nix
@@ -11,7 +11,8 @@
       opts,
       data,
     }: let
-      format = opts.format or "json";
+      _format = opts.format or "json";
+      format = if _format == "yaml" then "yaml_1_2" else _format;
       formatOpts = builtins.removeAttrs opts ["format"];
       formatter = formats.${format} formatOpts;
 
@@ -22,7 +23,7 @@
           lua = "--- Generated by soonix, DO NOT EDIT\n";
           xml = "<!-- Generated by soonix, DO NOT EDIT -->\n";
         }.${
-          format
+          _format
         } or "";
     in
       (formatter.generate name data).overrideAttrs (pre: {