diff --git a/library/Icinga/Test/BaseTestCase.php b/library/Icinga/Test/BaseTestCase.php
index 286ec3059..214b530ee 100644
--- a/library/Icinga/Test/BaseTestCase.php
+++ b/library/Icinga/Test/BaseTestCase.php
@@ -138,7 +138,7 @@ namespace Icinga\Test {
         /**
          * Setup MVC bootstrapping and ensure that the Icinga-Mock gets reinitialized
          */
-        public function setUp()
+        public function setUp(): void
         {
             parent::setUp();
             $this->setupIcingaMock();
diff --git a/modules/monitoring/test/php/application/views/helpers/PluginOutputTest.php b/modules/monitoring/test/php/application/views/helpers/PluginOutputTest.php
index a07614079..76e67c6ff 100644
--- a/modules/monitoring/test/php/application/views/helpers/PluginOutputTest.php
+++ b/modules/monitoring/test/php/application/views/helpers/PluginOutputTest.php
@@ -20,7 +20,7 @@ class PluginOutputTest extends BaseTestCase
 
     protected static $statusTags = array('OK', 'WARNING', 'CRITICAL', 'UNKNOWN', 'UP', 'DOWN');
 
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
 
diff --git a/modules/monitoring/test/php/regression/Bug7043Test.php b/modules/monitoring/test/php/regression/Bug7043Test.php
index 07cc02428..ba9291be6 100644
--- a/modules/monitoring/test/php/regression/Bug7043Test.php
+++ b/modules/monitoring/test/php/regression/Bug7043Test.php
@@ -24,7 +24,7 @@ class ConfigWithSetModuleConfig extends Config
 
 class Bug7043Test extends BaseTestCase
 {
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         Mockery::close(); // Necessary because some tests run in a separate process
diff --git a/test/php/application/views/helpers/DateFormatTestBroken.php b/test/php/application/views/helpers/DateFormatTestBroken.php
index 188c62988..6fb768b3c 100644
--- a/test/php/application/views/helpers/DateFormatTestBroken.php
+++ b/test/php/application/views/helpers/DateFormatTestBroken.php
@@ -12,7 +12,7 @@ require_once BaseTestCase::$appDir . '/views/helpers/DateFormat.php';
 
 class DateFormatTest extends BaseTestCase
 {
-    public function tearDown()
+    public function tearDown(): void
     {
         DateTimeFactory::setConfig(array('timezone' => date_default_timezone_get()));
     }
diff --git a/test/php/library/Icinga/Application/ClassLoaderTest.php b/test/php/library/Icinga/Application/ClassLoaderTest.php
index 542286912..7b88c6e74 100644
--- a/test/php/library/Icinga/Application/ClassLoaderTest.php
+++ b/test/php/library/Icinga/Application/ClassLoaderTest.php
@@ -26,7 +26,7 @@ class TestStruct
 
 EOD;
 
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $tempDir = sys_get_temp_dir();
@@ -35,7 +35,7 @@ EOD;
         file_put_contents($this->baseDir. self::$classFile, self::$classContent);
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         system('rm -rf '. $this->baseDir);
diff --git a/test/php/library/Icinga/Application/ConfigTest.php b/test/php/library/Icinga/Application/ConfigTest.php
index e47173679..f875cb5c7 100644
--- a/test/php/library/Icinga/Application/ConfigTest.php
+++ b/test/php/library/Icinga/Application/ConfigTest.php
@@ -11,7 +11,7 @@ class ConfigTest extends BaseTestCase
     /**
      * Set up config dir
      */
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->oldConfigDir = Config::$configDir;
@@ -21,7 +21,7 @@ class ConfigTest extends BaseTestCase
     /**
      * Reset config dir
      */
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         Config::$configDir = $this->oldConfigDir;
diff --git a/test/php/library/Icinga/Data/DataArray/ArrayDatasourceTest.php b/test/php/library/Icinga/Data/DataArray/ArrayDatasourceTest.php
index 5ad2b1b09..7e715cac2 100644
--- a/test/php/library/Icinga/Data/DataArray/ArrayDatasourceTest.php
+++ b/test/php/library/Icinga/Data/DataArray/ArrayDatasourceTest.php
@@ -10,7 +10,7 @@ class ArrayDatasourceTest extends BaseTestCase
 {
     private $sampleData;
 
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->sampleData = array(
diff --git a/test/php/library/Icinga/Data/Filter/FilterTest.php b/test/php/library/Icinga/Data/Filter/FilterTest.php
index 97133a216..9bbff01a3 100644
--- a/test/php/library/Icinga/Data/Filter/FilterTest.php
+++ b/test/php/library/Icinga/Data/Filter/FilterTest.php
@@ -61,7 +61,7 @@ class FilterTest extends BaseTestCase
 
     private $sampleData;
 
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->sampleData = array(
diff --git a/test/php/library/Icinga/File/Ini/IniParserTest.php b/test/php/library/Icinga/File/Ini/IniParserTest.php
index 5a1d7df90..b945cc44e 100644
--- a/test/php/library/Icinga/File/Ini/IniParserTest.php
+++ b/test/php/library/Icinga/File/Ini/IniParserTest.php
@@ -12,13 +12,13 @@ class IniParserTest extends BaseTestCase
 {
     protected $tempFile;
 
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         $this->tempFile = tempnam(sys_get_temp_dir(), 'icinga-ini-parser-test');
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         unlink($this->tempFile);
diff --git a/test/php/library/Icinga/File/Ini/IniWriterTest.php b/test/php/library/Icinga/File/Ini/IniWriterTest.php
index c3fb6df1f..acd9c9738 100644
--- a/test/php/library/Icinga/File/Ini/IniWriterTest.php
+++ b/test/php/library/Icinga/File/Ini/IniWriterTest.php
@@ -12,7 +12,7 @@ class IniWriterTest extends BaseTestCase
     protected $tempFile;
     protected $tempFile2;
 
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
 
@@ -20,7 +20,7 @@ class IniWriterTest extends BaseTestCase
         $this->tempFile2 = tempnam(sys_get_temp_dir(), 'icinga-ini-writer-test-2');
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
 
diff --git a/test/php/library/Icinga/Logger/Writer/StreamWriterTest.php b/test/php/library/Icinga/Logger/Writer/StreamWriterTest.php
index 38ff4dc0d..4570a2447 100644
--- a/test/php/library/Icinga/Logger/Writer/StreamWriterTest.php
+++ b/test/php/library/Icinga/Logger/Writer/StreamWriterTest.php
@@ -10,14 +10,14 @@ use Icinga\Test\BaseTestCase;
 
 class StreamWriterTest extends BaseTestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
 
         $this->target = tempnam(sys_get_temp_dir(), 'log');
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
 
diff --git a/test/php/library/Icinga/Test/BaseTestCaseTest.php b/test/php/library/Icinga/Test/BaseTestCaseTest.php
index 8611dbe62..2625d983d 100644
--- a/test/php/library/Icinga/Test/BaseTestCaseTest.php
+++ b/test/php/library/Icinga/Test/BaseTestCaseTest.php
@@ -10,7 +10,7 @@ class BaseTestCaseTest extends BaseTestCase
 {
     protected $emptySqlDumpFile;
 
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
 
diff --git a/test/php/library/Icinga/Util/TranslatorTest.php b/test/php/library/Icinga/Util/TranslatorTest.php
index d61ea4a9d..5696959a8 100644
--- a/test/php/library/Icinga/Util/TranslatorTest.php
+++ b/test/php/library/Icinga/Util/TranslatorTest.php
@@ -17,7 +17,7 @@ class TranslatorWithHardcodedLocaleCodes extends Translator
 
 class TranslatorTest extends BaseTestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
         Translator::registerDomain('icingatest', BaseTestCase::$testDir . '/res/locale');
diff --git a/test/php/library/Icinga/Web/FormTest.php b/test/php/library/Icinga/Web/FormTest.php
index 3d6ac7d1e..b0e85e749 100644
--- a/test/php/library/Icinga/Web/FormTest.php
+++ b/test/php/library/Icinga/Web/FormTest.php
@@ -26,7 +26,7 @@ class SuccessfulForm extends Form
 
 class FormTest extends BaseTestCase
 {
-    public function tearDown()
+    public function tearDown(): void
     {
         Mockery::close(); // Necessary as some tests are running isolated
     }
diff --git a/test/php/library/Icinga/Web/HookTest.php b/test/php/library/Icinga/Web/HookTest.php
index fdee11636..111b6be37 100644
--- a/test/php/library/Icinga/Web/HookTest.php
+++ b/test/php/library/Icinga/Web/HookTest.php
@@ -41,14 +41,14 @@ class HookTest extends BaseTestCase
     protected $failingHook   = '\\Tests\\Icinga\\Web\\FailingHook';
     protected $testBaseClass = '\\Icinga\\Web\\Hook\\TestHook';
 
-    public function setUp()
+    public function setUp(): void
     {
         $this->markTestSkipped();
         parent::setUp();
         Hook::clean();
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         Hook::clean();
diff --git a/test/php/library/Icinga/Web/Widget/DashboardTest.php b/test/php/library/Icinga/Web/Widget/DashboardTest.php
index 260e5b494..cb48952fe 100644
--- a/test/php/library/Icinga/Web/Widget/DashboardTest.php
+++ b/test/php/library/Icinga/Web/Widget/DashboardTest.php
@@ -39,7 +39,7 @@ class DashboardWithPredefinableActiveName extends Dashboard
 
 class DashboardTest extends BaseTestCase
 {
-    public function tearDown()
+    public function tearDown(): void
     {
         parent::tearDown();
         Mockery::close(); // Necessary because some tests run in a separate process
diff --git a/test/php/library/Icinga/Web/Widget/SearchDashboardTest.php b/test/php/library/Icinga/Web/Widget/SearchDashboardTest.php
index 7370338e5..6fe7e2118 100644
--- a/test/php/library/Icinga/Web/Widget/SearchDashboardTest.php
+++ b/test/php/library/Icinga/Web/Widget/SearchDashboardTest.php
@@ -11,7 +11,7 @@ use Icinga\Web\Widget\SearchDashboard;
 
 class SearchDashboardTest extends BaseTestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
         $moduleMock = Mockery::mock('Icinga\Application\Modules\Module');
         $searchUrl = (object) array(