diff --git a/src/tools/yaml-to-json-converter/yaml-to-json.e2e.spec.ts b/src/tools/yaml-to-json-converter/yaml-to-json.e2e.spec.ts
index 7b2a2d18..d6ed84c3 100644
--- a/src/tools/yaml-to-json-converter/yaml-to-json.e2e.spec.ts
+++ b/src/tools/yaml-to-json-converter/yaml-to-json.e2e.spec.ts
@@ -28,4 +28,53 @@ test.describe('Tool - Yaml to json', () => {
    `.trim(),
     );
   });
+
+  test('Yaml is parsed with merge key and output correct json', async ({ page }) => {
+    await page.getByTestId('input').fill(`
+      default: &default
+        name: ''
+        age: 0
+
+      person:
+        *default
+
+      persons:
+      - <<: *default
+        age: 1
+      - <<: *default
+        name: John
+      - { age: 3, <<: *default }
+      
+      `);
+
+    const generatedJson = await page.getByTestId('area-content').innerText();
+
+    expect(generatedJson.trim()).toEqual(
+      `
+{
+   "default": {
+      "name": "",
+      "age": 0
+   },
+   "person": {
+      "name": "",
+      "age": 0
+   },
+   "persons": [
+      {
+         "name": "",
+         "age": 1
+      },
+      {
+         "name": "John",
+         "age": 0
+      },
+      {
+         "age": 3,
+         "name": ""
+      }
+   ]
+}`.trim(),
+    );
+  });
 });
diff --git a/src/tools/yaml-to-json-converter/yaml-to-json.vue b/src/tools/yaml-to-json-converter/yaml-to-json.vue
index 39c9297f..72608add 100644
--- a/src/tools/yaml-to-json-converter/yaml-to-json.vue
+++ b/src/tools/yaml-to-json-converter/yaml-to-json.vue
@@ -6,7 +6,7 @@ import { withDefaultOnError } from '@/utils/defaults';
 
 function transformer(value: string) {
   return withDefaultOnError(() => {
-    const obj = parseYaml(value);
+    const obj = parseYaml(value, { merge: true });
     return obj ? JSON.stringify(obj, null, 3) : '';
   }, '');
 }