diff --git a/test/phpunit/AdminLibTest.php b/test/phpunit/AdminLibTest.php
index 9ce135da263..317d486434e 100644
--- a/test/phpunit/AdminLibTest.php
+++ b/test/phpunit/AdminLibTest.php
@@ -78,7 +78,7 @@ class AdminLibTest extends PHPUnit\Framework\TestCase
 	 *
 	 * @return void
 	 */
-	public static function setUpBeforeClass()
+	public static function setUpBeforeClass(): void
 	{
 		global $conf,$user,$langs,$db;
 		$db->begin(); // This is to have all actions inside a transaction even if test launched without suite.
@@ -91,7 +91,7 @@ class AdminLibTest extends PHPUnit\Framework\TestCase
 	 *
 	 * @return	void
 	 */
-	public static function tearDownAfterClass()
+	public static function tearDownAfterClass(): void
 	{
 		global $conf,$user,$langs,$db;
 		$db->rollback();
@@ -104,7 +104,7 @@ class AdminLibTest extends PHPUnit\Framework\TestCase
 	 *
 	 * @return  void
 	 */
-	protected function setUp()
+	protected function setUp(): void
 	{
 		global $conf,$user,$langs,$db;
 		$conf=$this->savconf;
@@ -119,7 +119,7 @@ class AdminLibTest extends PHPUnit\Framework\TestCase
 	 *
 	 * @return	void
 	 */
-	protected function tearDown()
+	protected function tearDown(): void
 	{
 		print __METHOD__."\n";
 	}