diff --git a/examples/api-tests/src/launch-preferences.spec.js b/examples/api-tests/src/launch-preferences.spec.js
index 895362de96da4..7d0ed25785b95 100644
--- a/examples/api-tests/src/launch-preferences.spec.js
+++ b/examples/api-tests/src/launch-preferences.spec.js
@@ -25,7 +25,7 @@
  * Expectations should be tested and aligned against VS Code.
  * See https://github.com/akosyakov/vscode-launch/blob/master/src/test/extension.test.ts
  */
-describe.skip('Launch Preferences', function () {
+describe('Launch Preferences', function () {
     this.timeout(10_000);
 
     const { assert } = chai;
diff --git a/packages/core/src/browser/preferences/preference-provider.spec.ts b/packages/core/src/browser/preferences/preference-provider.spec.ts
deleted file mode 100644
index dd692f9566506..0000000000000
--- a/packages/core/src/browser/preferences/preference-provider.spec.ts
+++ /dev/null
@@ -1,36 +0,0 @@
-// *****************************************************************************
-// Copyright (C) 2023 EclipseSource and others.
-//
-// This program and the accompanying materials are made available under the
-// terms of the Eclipse Public License v. 2.0 which is available at
-// http://www.eclipse.org/legal/epl-2.0.
-//
-// This Source Code may also be made available under the following Secondary
-// Licenses when the conditions for such availability set forth in the Eclipse
-// Public License v. 2.0 are satisfied: GNU General Public License, version 2
-// with the GNU Classpath Exception which is available at
-// https://www.gnu.org/software/classpath/license.html.
-//
-// SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
-// *****************************************************************************
-
-import { PreferenceProvider } from './preference-provider';
-const { expect } = require('chai');
-
-describe('PreferenceProvider', () => {
-    it('should preserve extra source fields on merge', () => {
-        const result = PreferenceProvider.merge({ 'configurations': [], 'compounds': [] }, { 'configurations': [] });
-        expect(result).deep.equals({ 'configurations': [], 'compounds': [] });
-    });
-    it('should preserve extra target fields on merge', () => {
-        const result = PreferenceProvider.merge({ 'configurations': [] }, { 'configurations': [], 'compounds': [] });
-        expect(result).deep.equals({ 'configurations': [], 'compounds': [] });
-    });
-    it('should merge array values', () => {
-        const result = PreferenceProvider.merge(
-            { 'configurations': [{ 'name': 'test1', 'request': 'launch' }], 'compounds': [] },
-            { 'configurations': [{ 'name': 'test2' }] }
-        );
-        expect(result).deep.equals({ 'configurations': [{ 'name': 'test1', 'request': 'launch' }, { 'name': 'test2' }], 'compounds': [] });
-    });
-});
diff --git a/packages/core/src/browser/preferences/preference-provider.ts b/packages/core/src/browser/preferences/preference-provider.ts
index 8b6b490708803..a4f0a9faf7f68 100644
--- a/packages/core/src/browser/preferences/preference-provider.ts
+++ b/packages/core/src/browser/preferences/preference-provider.ts
@@ -235,9 +235,6 @@ export abstract class PreferenceProvider implements Disposable {
                 if (JSONExt.isObject(source[key]) && JSONExt.isObject(value)) {
                     this.merge(source[key], value);
                     continue;
-                } else if (JSONExt.isArray(source[key]) && JSONExt.isArray(value)) {
-                    source[key] = [...JSONExt.deepCopy(source[key] as any), ...JSONExt.deepCopy(value)];
-                    continue;
                 }
             }
             source[key] = JSONExt.deepCopy(value);