diff --git a/.github/workflows/ftp.yml b/.github/workflows/ftp.yml
index aa9fe3aad79136175662379a78b3a6379884bc77..be2d2ba02547470b9ff7e67a1c358850ffd30242 100644
--- a/.github/workflows/ftp.yml
+++ b/.github/workflows/ftp.yml
@@ -43,7 +43,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php-versions }}
-          tools: phpunit
+          tools: phpunit:9
           extensions: mbstring, fileinfo, intl, sqlite, pdo_sqlite, zip, gd
 
       - name: Set up Nextcloud
diff --git a/.github/workflows/s3-external.yml b/.github/workflows/s3-external.yml
index dedab6b0c16fbdde752121313befc0f4b58e9492..8931f35277c76fc9c77853706f89ea74db0a2be6 100644
--- a/.github/workflows/s3-external.yml
+++ b/.github/workflows/s3-external.yml
@@ -44,7 +44,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php-versions }}
-          tools: phpunit
+          tools: phpunit:9
           extensions: mbstring, fileinfo, intl, sqlite, pdo_sqlite, zip, gd
 
       - name: Set up Nextcloud
@@ -93,7 +93,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php-versions }}
-          tools: phpunit
+          tools: phpunit:9
           extensions: mbstring, fileinfo, intl, sqlite, pdo_sqlite, zip, gd
 
       - name: Set up Nextcloud
diff --git a/.github/workflows/s3-primary.yml b/.github/workflows/s3-primary.yml
index a6ee0970adaa44a5acb08f31e59ceeca5f6dcafe..aad0f2a1b621a1243680ccd268d0042514882d46 100644
--- a/.github/workflows/s3-primary.yml
+++ b/.github/workflows/s3-primary.yml
@@ -38,7 +38,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php-versions }}
-          tools: phpunit
+          tools: phpunit:9
           extensions: mbstring, fileinfo, intl, sqlite, pdo_sqlite, zip, gd
 
       - name: Set up Nextcloud
diff --git a/apps/updatenotification/tests/Settings/AdminTest.php b/apps/updatenotification/tests/Settings/AdminTest.php
index 852504fb45aa4122973aabbd2168ad940fc67c4d..15b5b2b450af0213e921ccf3d5e1d0bb6c1e87b6 100644
--- a/apps/updatenotification/tests/Settings/AdminTest.php
+++ b/apps/updatenotification/tests/Settings/AdminTest.php
@@ -29,6 +29,7 @@ declare(strict_types=1);
  */
 namespace OCA\UpdateNotification\Tests\Settings;
 
+use OC\User\Backend;
 use OCA\UpdateNotification\Settings\Admin;
 use OCA\UpdateNotification\UpdateChecker;
 use OCP\AppFramework\Http\TemplateResponse;
@@ -39,6 +40,8 @@ use OCP\IGroupManager;
 use OCP\L10N\IFactory;
 use OCP\L10N\ILanguageIterator;
 use OCP\Support\Subscription\IRegistry;
+use OCP\User\Backend\ICountUsersBackend;
+use OCP\UserInterface;
 use OCP\Util;
 use Test\TestCase;
 use OCP\IUserManager;
@@ -77,11 +80,11 @@ class AdminTest extends TestCase {
 		$this->logger = $this->createMock(LoggerInterface::class);
 
 		$this->admin = new Admin(
-			$this->config, 
-			$this->updateChecker, 
-			$this->groupManager, 
-			$this->dateTimeFormatter, 
-			$this->l10nFactory, 
+			$this->config,
+			$this->updateChecker,
+			$this->groupManager,
+			$this->dateTimeFormatter,
+			$this->l10nFactory,
 			$this->subscriptionRegistry,
 			$this->userManager,
 			$this->logger
@@ -89,9 +92,9 @@ class AdminTest extends TestCase {
 	}
 
 	public function testGetFormWithUpdate() {
-		$backend1 = $this->createMock(UserInterface::class);
-		$backend2 = $this->createMock(UserInterface::class);
-		$backend3 = $this->createMock(UserInterface::class);
+		$backend1 = $this->createMock(CountUsersBackend::class);
+		$backend2 = $this->createMock(CountUsersBackend::class);
+		$backend3 = $this->createMock(CountUsersBackend::class);
 		$backend1
 			->expects($this->once())
 			->method('implementsActions')
@@ -213,9 +216,9 @@ class AdminTest extends TestCase {
 	}
 
 	public function testGetFormWithUpdateAndChangedUpdateServer() {
-		$backend1 = $this->createMock(UserInterface::class);
-		$backend2 = $this->createMock(UserInterface::class);
-		$backend3 = $this->createMock(UserInterface::class);
+		$backend1 = $this->createMock(CountUsersBackend::class);
+		$backend2 = $this->createMock(CountUsersBackend::class);
+		$backend3 = $this->createMock(CountUsersBackend::class);
 		$backend1
 			->expects($this->once())
 			->method('implementsActions')
@@ -337,9 +340,9 @@ class AdminTest extends TestCase {
 	}
 
 	public function testGetFormWithUpdateAndCustomersUpdateServer() {
-		$backend1 = $this->createMock(UserInterface::class);
-		$backend2 = $this->createMock(UserInterface::class);
-		$backend3 = $this->createMock(UserInterface::class);
+		$backend1 = $this->createMock(CountUsersBackend::class);
+		$backend2 = $this->createMock(CountUsersBackend::class);
+		$backend3 = $this->createMock(CountUsersBackend::class);
 		$backend1
 			->expects($this->once())
 			->method('implementsActions')
@@ -543,3 +546,7 @@ class AdminTest extends TestCase {
 		$this->assertSame($expectation, $result);
 	}
 }
+
+abstract class CountUsersBackend implements UserInterface, ICountUsersBackend {
+
+}
diff --git a/tests/lib/Encryption/UtilTest.php b/tests/lib/Encryption/UtilTest.php
index 02155be11ddab2fb4416dced481ab1729325fff4..84d81dd1cbb4bed1dc64ac4f36ff3306fa182f46 100644
--- a/tests/lib/Encryption/UtilTest.php
+++ b/tests/lib/Encryption/UtilTest.php
@@ -4,8 +4,6 @@ namespace Test\Encryption;
 
 use OC\Encryption\Util;
 use OC\Files\View;
-use OCA\Files_External\Lib\StorageConfig;
-use OCA\Files_External\Service\GlobalStoragesService;
 use OCP\Encryption\IEncryptionModule;
 use OCP\IConfig;
 use Test\TestCase;
@@ -190,43 +188,4 @@ class UtilTest extends TestCase {
 			['/foo/test.txt.ocTransferId7567.part', '/foo/test.txt'],
 		];
 	}
-
-	public function dataTestIsSystemWideMountPoint() {
-		return [
-			[false, 'non-matching mount point name', [], [], '/mp_another'],
-			[true, 'applicable to all', [], []],
-			[true, 'applicable to user directly', ['user1'], []],
-			[true, 'applicable to group directly', [], ['group1']],
-			[false, 'non-applicable to current user', ['user2'], []],
-			[false, 'non-applicable to current user\'s group', [], ['group2']],
-			[true, 'mount point without leading slash', [], [], 'mp'],
-		];
-	}
-
-	/**
-	 * @dataProvider dataTestIsSystemWideMountPoint
-	 */
-	public function testIsSystemWideMountPoint($expectedResult, $expectationText, $applicableUsers, $applicableGroups, $mountPointName = '/mp') {
-		$this->groupManager->method('isInGroup')
-			 ->will($this->returnValueMap([
-			 	['user1', 'group1', true], // user is only in group1
-			 	['user1', 'group2', false],
-			 ]));
-
-		$storages = [];
-
-		$storageConfig = $this->createMock(StorageConfig::class);
-		$storageConfig->method('getMountPoint')->willReturn($mountPointName);
-		$storageConfig->method('getApplicableUsers')->willReturn($applicableUsers);
-		$storageConfig->method('getApplicableGroups')->willReturn($applicableGroups);
-		$storages[] = $storageConfig;
-
-		$storagesServiceMock = $this->createMock(GlobalStoragesService::class);
-		$storagesServiceMock->expects($this->atLeastOnce())->method('getAllStorages')
-			->willReturn($storages);
-
-		$this->overwriteService(GlobalStoragesService::class, $storagesServiceMock);
-
-		$this->assertEquals($expectedResult, $this->util->isSystemWideMountPoint('/files/mp', 'user1'), 'Test case: ' . $expectationText);
-	}
 }