diff --git a/core/package.json b/core/package.json
index 0c4f8d3a..3f720633 100644
--- a/core/package.json
+++ b/core/package.json
@@ -155,7 +155,7 @@
     "vfile-statistics": "2.0.0",
     "what-input": "5.2.12",
     "what-the-diff": "0.6.0",
-    "yaml": "1.10.2"
+    "yaml": "2.1.3"
   },
   "devDependencies": {
     "@babel/cli": "7.19.3",
diff --git a/core/src/formats/YamlFormatter.ts b/core/src/formats/YamlFormatter.ts
index c2332d2c..0a331dd1 100644
--- a/core/src/formats/YamlFormatter.ts
+++ b/core/src/formats/YamlFormatter.ts
@@ -1,20 +1,21 @@
-import yaml from 'yaml';
+import yaml, { isNode, isMap } from 'yaml';
 
 import { sortKeys } from './helpers';
 import FileFormatter from './FileFormatter';
+import { isNotNullish } from '../lib/util/null.util';
 
-import type { Pair, YAMLMap, YAMLSeq } from 'yaml/types';
+import type { Pair, YAMLMap, Node } from 'yaml';
 
 function addComments(items: Array<Pair>, comments: Record<string, string>, prefix = '') {
   items.forEach(item => {
-    if (item.key !== undefined) {
-      const itemKey = item.key.toString();
+    if (isNotNullish(item.key)) {
+      const itemKey = item.key?.toString() ?? '';
       const key = prefix ? `${prefix}.${itemKey}` : itemKey;
-      if (comments[key]) {
+      if (isNode(item.key) && comments[key]) {
         const value = comments[key].split('\\n').join('\n ');
-        item.commentBefore = ` ${value}`;
+        item.key.commentBefore = ` ${value}`;
       }
-      if (Array.isArray(item.value?.items)) {
+      if (isMap(item.value)) {
         addComments(item.value.items, comments, key);
       }
     }
@@ -30,12 +31,12 @@ class YamlFormatter extends FileFormatter {
   }
 
   toFile(data: object, sortedKeys: string[] = [], comments: Record<string, string> = {}) {
-    const contents = yaml.createNode(data) as YAMLMap | YAMLSeq;
+    const doc = new yaml.Document();
+    const contents = doc.createNode(data) as YAMLMap<Node>;
 
-    addComments(contents.items, comments);
+    addComments(contents.items as Pair<Node>[], comments);
 
     contents.items.sort(sortKeys(sortedKeys, item => item.key?.toString()));
-    const doc = new yaml.Document();
     doc.contents = contents;
 
     return doc.toString();
diff --git a/core/src/formats/__tests__/YamlFormatter.spec.ts b/core/src/formats/__tests__/YamlFormatter.spec.ts
new file mode 100644
index 00000000..2ba22ede
--- /dev/null
+++ b/core/src/formats/__tests__/YamlFormatter.spec.ts
@@ -0,0 +1,69 @@
+import yamlFormatter from '../YamlFormatter';
+
+const json = {
+  keyF: 'valueF',
+  keyA: 'valueA',
+  keyB: 'valueB',
+  keyD: 'valueD',
+  keyC: 'valueC',
+  keyE: 'valueE',
+};
+
+const unsortedYaml = `keyF: valueF
+keyA: valueA
+keyB: valueB
+keyD: valueD
+keyC: valueC
+keyE: valueE
+`;
+
+const sortedYaml = `keyA: valueA
+keyB: valueB
+keyC: valueC
+keyD: valueD
+keyE: valueE
+keyF: valueF
+`;
+
+const sortedCommentedYaml = `keyA: valueA
+# New comment here
+keyB: valueB
+keyC: valueC
+keyD: valueD
+keyE: valueE
+# Last comment
+keyF: valueF
+`;
+
+describe('YamlFormatter', () => {
+  describe('toFile', () => {
+    it('should convert json to yaml', () => {
+      expect(yamlFormatter.toFile(json)).toEqual(unsortedYaml);
+    });
+
+    it('should sort yaml', () => {
+      expect(yamlFormatter.toFile(json, ['keyA', 'keyB', 'keyC', 'keyD', 'keyE', 'keyF'])).toEqual(
+        sortedYaml,
+      );
+    });
+
+    it('should add comments', () => {
+      expect(
+        yamlFormatter.toFile(json, ['keyA', 'keyB', 'keyC', 'keyD', 'keyE', 'keyF'], {
+          keyB: 'New comment here',
+          keyF: 'Last comment',
+        }),
+      ).toEqual(sortedCommentedYaml);
+    });
+  });
+
+  describe('fromFile', () => {
+    it('should convert yaml to json', () => {
+      expect(yamlFormatter.fromFile(unsortedYaml)).toEqual(json);
+    });
+
+    it('should handle yaml with comments', () => {
+      expect(yamlFormatter.fromFile(sortedCommentedYaml)).toEqual(json);
+    });
+  });
+});
diff --git a/core/yarn.lock b/core/yarn.lock
index 122465c6..005695c2 100644
--- a/core/yarn.lock
+++ b/core/yarn.lock
@@ -12104,7 +12104,12 @@ yallist@^4.0.0:
   resolved "https://registry.yarnpkg.com/yallist/-/yallist-4.0.0.tgz#9bb92790d9c0effec63be73519e11a35019a3a72"
   integrity sha512-3wdGidZyq5PB084XLES5TpOSRA3wjXAlIWMhum2kRcv/41Sn2emQ0dycQW4uZXLejwKvg6EsvbdlVL+FYEct7A==
 
-yaml@1.10.2, yaml@^1.10.0:
+yaml@2.1.3:
+  version "2.1.3"
+  resolved "https://registry.yarnpkg.com/yaml/-/yaml-2.1.3.tgz#9b3a4c8aff9821b696275c79a8bee8399d945207"
+  integrity sha512-AacA8nRULjKMX2DvWvOAdBZMOfQlypSFkjcOcu9FalllIDJ1kvlREzcdIZmidQUqqeMv7jorHjq2HlLv/+c2lg==
+
+yaml@^1.10.0:
   version "1.10.2"
   resolved "https://registry.yarnpkg.com/yaml/-/yaml-1.10.2.tgz#2301c5ffbf12b467de8da2333a459e29e7920e4b"
   integrity sha512-r3vXyErRCYJ7wg28yvBY5VSoAF8ZvlcW9/BwUzEtUsjvX/DKs24dIkuwjtuprwJJHsbyUbLApepYTR1BN4uHrg==