diff --git a/tests/legacy/ApiTest.php b/tests/legacy/ApiTest.php
index 265f502f0..89bddf31d 100644
--- a/tests/legacy/ApiTest.php
+++ b/tests/legacy/ApiTest.php
@@ -22,6 +22,8 @@ require_once __DIR__ . '/../../include/api.php';
  *
  * Functions that use header() need to be tested in a separate process.
  * @see https://phpunit.de/manual/5.7/en/appendixes.annotations.html#appendixes.annotations.runTestsInSeparateProcesses
+ *
+ * @backupGlobals enabled
  */
 class ApiTest extends FixtureTest
 {
@@ -108,10 +110,6 @@ class ApiTest extends FixtureTest
 			'authenticated' => true,
 			'uid'           => $this->selfUser['id']
 		];
-
-		$_POST   = [];
-		$_GET    = [];
-		$_SERVER = [];
 	}
 
 	/**
@@ -140,7 +138,7 @@ class ApiTest extends FixtureTest
 	 *
 	 * @return void
 	 */
-	private function assertOtherUser(array $user)
+	private function assertOtherUser(array $user = [])
 	{
 		self::assertEquals($this->otherUser['id'], $user['id']);
 		self::assertEquals($this->otherUser['id'], $user['id_str']);
@@ -157,10 +155,10 @@ class ApiTest extends FixtureTest
 	 *
 	 * @return void
 	 */
-	private function assertStatus(array $status)
+	private function assertStatus(array $status = [])
 	{
-		self::assertInternalType('string', $status['text']);
-		self::assertInternalType('int', $status['id']);
+		self::assertInternalType('string', $status['text'] ?? '');
+		self::assertInternalType('int', $status['id'] ?? '');
 		// We could probably do more checks here.
 	}
 
@@ -171,7 +169,7 @@ class ApiTest extends FixtureTest
 	 *
 	 * @return void
 	 */
-	private function assertList(array $list)
+	private function assertList(array $list = [])
 	{
 		self::assertInternalType('string', $list['name']);
 		self::assertInternalType('int', $list['id']);
@@ -188,7 +186,7 @@ class ApiTest extends FixtureTest
 	 *
 	 * @return void
 	 */
-	private function assertXml($result, $root_element)
+	private function assertXml($result = '', $root_element = '')
 	{
 		self::assertStringStartsWith('<?xml version="1.0"?>', $result);
 		self::assertContains('<' . $root_element, $result);
@@ -304,6 +302,7 @@ class ApiTest extends FixtureTest
 	 *
 	 * @return void
 	 * @runInSeparateProcess
+	 * @preserveGlobalState disabled
 	 * @expectedException Friendica\Network\HTTPException\UnauthorizedException
 	 */
 	public function testApiLoginWithoutLogin()
@@ -316,6 +315,7 @@ class ApiTest extends FixtureTest
 	 *
 	 * @return void
 	 * @runInSeparateProcess
+	 * @preserveGlobalState disabled
 	 * @expectedException Friendica\Network\HTTPException\UnauthorizedException
 	 */
 	public function testApiLoginWithBadLogin()
@@ -349,6 +349,7 @@ class ApiTest extends FixtureTest
 	 *
 	 * @return void
 	 * @runInSeparateProcess
+	 * @doesNotPerformAssertions
 	 */
 	public function testApiLoginWithCorrectLogin()
 	{
@@ -1312,8 +1313,8 @@ class ApiTest extends FixtureTest
 
 	/**
 	 * Test the api_media_upload() function.
-	 *
-	 * @return void
+	 * @runInSeparateProcess
+	 * @preserveGlobalState disabled
 	 * @expectedException Friendica\Network\HTTPException\BadRequestException
 	 */
 	public function testApiMediaUpload()
@@ -1504,7 +1505,7 @@ class ApiTest extends FixtureTest
 		$result             = api_search('json');
 		foreach ($result['status'] as $status) {
 			self::assertStatus($status);
-			self::assertContains('reply', $status['text'], null, true);
+			self::assertContains('reply', $status['text'], '', true);
 		}
 	}
 
@@ -1520,7 +1521,7 @@ class ApiTest extends FixtureTest
 		$result            = api_search('json');
 		foreach ($result['status'] as $status) {
 			self::assertStatus($status);
-			self::assertContains('reply', $status['text'], null, true);
+			self::assertContains('reply', $status['text'], '', true);
 		}
 	}
 
@@ -1536,14 +1537,13 @@ class ApiTest extends FixtureTest
 		$result          = api_search('json');
 		foreach ($result['status'] as $status) {
 			self::assertStatus($status);
-			self::assertContains('reply', $status['text'], null, true);
+			self::assertContains('reply', $status['text'], '', true);
 		}
 	}
 
 	/**
 	 * Test the api_search() function with an q parameter contains hashtag.
-	 *
-	 * @return void
+	 * @doesNotPerformAssertions
 	 */
 	public function testApiSearchWithHashtag()
 	{
@@ -1551,14 +1551,13 @@ class ApiTest extends FixtureTest
 		$result        = api_search('json');
 		foreach ($result['status'] as $status) {
 			self::assertStatus($status);
-			self::assertContains('#friendica', $status['text'], null, true);
+			self::assertContains('#friendica', $status['text'], '', true);
 		}
 	}
 
 	/**
 	 * Test the api_search() function with an exclude_replies parameter.
-	 *
-	 * @return void
+	 * @doesNotPerformAssertions
 	 */
 	public function testApiSearchWithExcludeReplies()
 	{
@@ -2474,8 +2473,7 @@ class ApiTest extends FixtureTest
 
 	/**
 	 * Test the api_format_items() function.
-	 *
-	 * @return void
+	 * @doesNotPerformAssertions
 	 */
 	public function testApiFormatItems()
 	{
@@ -2500,8 +2498,7 @@ class ApiTest extends FixtureTest
 
 	/**
 	 * Test the api_format_items() function with an XML result.
-	 *
-	 * @return void
+	 * @doesNotPerformAssertions
 	 */
 	public function testApiFormatItemsWithXml()
 	{
@@ -2617,8 +2614,7 @@ class ApiTest extends FixtureTest
 
 	/**
 	 * Test the api_lists_statuses() function with a list ID.
-	 *
-	 * @return void
+	 * @doesNotPerformAssertions
 	 */
 	public function testApiListsStatusesWithListId()
 	{
@@ -3271,8 +3267,6 @@ class ApiTest extends FixtureTest
 
 	/**
 	 * Test the api_fr_photo_create_update() function.
-	 *
-	 * @return void
 	 * @expectedException Friendica\Network\HTTPException\BadRequestException
 	 */
 	public function testApiFrPhotoCreateUpdate()
diff --git a/tests/src/Core/Cache/ArrayCacheTest.php b/tests/src/Core/Cache/ArrayCacheTest.php
index 6ce6d4c1f..2d8d0ff83 100644
--- a/tests/src/Core/Cache/ArrayCacheTest.php
+++ b/tests/src/Core/Cache/ArrayCacheTest.php
@@ -40,6 +40,7 @@ class ArrayCacheTest extends MemoryCacheTest
 	public function testTTL()
 	{
 		// Array Cache doesn't support TTL
+		self::markTestSkipped("Array Cache doesn't support TTL");
 		return true;
 	}
 }
diff --git a/tests/src/Core/InstallerTest.php b/tests/src/Core/InstallerTest.php
index 365502e46..b3f91e7d3 100644
--- a/tests/src/Core/InstallerTest.php
+++ b/tests/src/Core/InstallerTest.php
@@ -463,10 +463,11 @@ class InstallerTest extends MockedTest
 
 	/**
 	 * Test the setup of the config cache for installation
+	 * @doesNotPerformAssertions
 	 */
 	public function testSetUpCache()
 	{
-		$this->l10nMock->shouldReceive('t')->andReturnUsing(function ($args) { return $args; });
+		$this->l10nMock->shouldReceive('t')->andReturnUsing(function ($args) { return $args; })->times(5);
 
 		$install = new Installer();
 		$configCache = Mockery::mock(Cache::class);
diff --git a/tests/src/Core/Lock/ArrayCacheLockTest.php b/tests/src/Core/Lock/ArrayCacheLockTest.php
index 727b9724a..6ddedfa43 100644
--- a/tests/src/Core/Lock/ArrayCacheLockTest.php
+++ b/tests/src/Core/Lock/ArrayCacheLockTest.php
@@ -33,7 +33,6 @@ class ArrayCacheLockTest extends LockTest
 
 	public function testLockTTL()
 	{
-		// ArrayCache doesn't support TTL
-		return true;
+		self::markTestSkipped("ArrayCache doesn't support TTL");
 	}
 }
diff --git a/tests/src/Core/Lock/SemaphoreLockTest.php b/tests/src/Core/Lock/SemaphoreLockTest.php
index dc7b9ee41..71273fdc2 100644
--- a/tests/src/Core/Lock/SemaphoreLockTest.php
+++ b/tests/src/Core/Lock/SemaphoreLockTest.php
@@ -61,8 +61,7 @@ class SemaphoreLockTest extends LockTest
 
 	public function testLockTTL()
 	{
-		// Semaphore doesn't work with TTL
-		return true;
+		self::markTestSkipped("Semaphore doesn't work with TTL");
 	}
 
 	/**
diff --git a/tests/src/Security/TwoFactor/Factory/TrustedBrowserTest.php b/tests/src/Security/TwoFactor/Factory/TrustedBrowserTest.php
index 5b2b6111c..0a093db5a 100644
--- a/tests/src/Security/TwoFactor/Factory/TrustedBrowserTest.php
+++ b/tests/src/Security/TwoFactor/Factory/TrustedBrowserTest.php
@@ -3,11 +3,12 @@
 namespace Friendica\Test\src\Security\TwoFactor\Factory;
 
 use Friendica\Security\TwoFactor\Factory\TrustedBrowser;
+use Friendica\Test\MockedTest;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Logger\VoidLogger;
 use Friendica\Util\Strings;
 
-class TrustedBrowserTest extends \PHPUnit_Framework_TestCase
+class TrustedBrowserTest extends MockedTest
 {
 	public function testCreateFromTableRowSuccess()
 	{
diff --git a/tests/src/Security/TwoFactor/Model/TrustedBrowserTest.php b/tests/src/Security/TwoFactor/Model/TrustedBrowserTest.php
index d89527374..eae7f580f 100644
--- a/tests/src/Security/TwoFactor/Model/TrustedBrowserTest.php
+++ b/tests/src/Security/TwoFactor/Model/TrustedBrowserTest.php
@@ -3,10 +3,11 @@
 namespace Friendica\Test\src\Security\TwoFactor\Model;
 
 use Friendica\Security\TwoFactor\Model\TrustedBrowser;
+use Friendica\Test\MockedTest;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Strings;
 
-class TrustedBrowserTest extends \PHPUnit_Framework_TestCase
+class TrustedBrowserTest extends MockedTest
 {
 	public function test__construct()
 	{
diff --git a/tests/src/Util/Logger/ProfilerLoggerTest.php b/tests/src/Util/Logger/ProfilerLoggerTest.php
index 81a94a466..9dd82b427 100644
--- a/tests/src/Util/Logger/ProfilerLoggerTest.php
+++ b/tests/src/Util/Logger/ProfilerLoggerTest.php
@@ -52,6 +52,7 @@ class ProfilerLoggerTest extends MockedTest
 	/**
 	 * Test if the profiler is profiling data
 	 * @dataProvider dataTests
+	 * @doesNotPerformAssertions
 	 */
 	public function testProfiling($function, $message, array $context)
 	{
@@ -64,6 +65,7 @@ class ProfilerLoggerTest extends MockedTest
 
 	/**
 	 * Test the log() function
+	 * @doesNotPerformAssertions
 	 */
 	public function testProfilingLog()
 	{
diff --git a/tests/src/Util/Logger/SyslogLoggerTest.php b/tests/src/Util/Logger/SyslogLoggerTest.php
index 67c726e25..61c0d874a 100644
--- a/tests/src/Util/Logger/SyslogLoggerTest.php
+++ b/tests/src/Util/Logger/SyslogLoggerTest.php
@@ -95,6 +95,7 @@ class SyslogLoggerTest extends AbstractLoggerTest
 
 	/**
 	 * Test the close() method
+	 * @doesNotPerformAssertions
 	 */
 	public function testClose()
 	{
diff --git a/tests/src/Util/Logger/VoidLoggerTest.php b/tests/src/Util/Logger/VoidLoggerTest.php
index bea2bc404..75b2d1a8b 100644
--- a/tests/src/Util/Logger/VoidLoggerTest.php
+++ b/tests/src/Util/Logger/VoidLoggerTest.php
@@ -32,6 +32,7 @@ class VoidLoggerTest extends MockedTest
 	/**
 	 * Test if the profiler is profiling data
 	 * @dataProvider dataTests
+	 * @doesNotPerformAssertions
 	 */
 	public function testNormal($function, $message, array $context)
 	{
@@ -41,6 +42,7 @@ class VoidLoggerTest extends MockedTest
 
 	/**
 	 * Test the log() function
+	 * @doesNotPerformAssertions
 	 */
 	public function testProfilingLog()
 	{