diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c7bb222..ed4b864 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -4,7 +4,7 @@
     
   # Install git (the php image doesn't have it) which is required by composer
   apt-get update -yq
-  apt-get install git wget procps -y
+  apt-get install git wget procps unzip -y
 
   # Install pcntl and redis extentions
   pecl install -o -f redis \
@@ -17,55 +17,17 @@
 
   # Install Composer
   wget https://getcomposer.org/composer.phar
-  php composer.phar install
+  php composer.phar install --dev
 
 services:
   - redis:latest
 
-# Test PHP 7.0
-test:7.0:
-  image: php:7.0
+# Test PHP 7.4
+test:7.4:
+  image: php:7.4
   before_script:
     - *docker_boostrap
   script:
-    - curl --location --output /usr/local/bin/phpunit https://phar.phpunit.de/phpunit-6.5.9.phar
-    - chmod +x /usr/local/bin/phpunit
-    - phpunit --verbose --configuration phpunit.xml.dist
+    - php vendor/bin/phpunit --verbose --configuration phpunit.xml.dist
   tags:
-    - docker
-
-# Test PHP 7.1
-test:7.1:
-  image: php:7.1
-  before_script:
-    - *docker_boostrap
-  script:
-    - curl --location --output /usr/local/bin/phpunit https://phar.phpunit.de/phpunit-7.5.9.phar
-    - chmod +x /usr/local/bin/phpunit
-    - phpunit --verbose --configuration phpunit.xml.dist
-  tags:
-    - docker
-
-# Test PHP 7.2
-test:7.2:
-  image: php:7.2
-  before_script:
-    - *docker_boostrap
-  script:
-    - curl --location --output /usr/local/bin/phpunit https://phar.phpunit.de/phpunit-7.5.9.phar
-    - chmod +x /usr/local/bin/phpunit
-    - phpunit --verbose --configuration phpunit.xml.dist
-  tags:
-    - docker
-
-# Test PHP 7.3
-test:7.3:
-  image: php:7.3
-  before_script:
-    - *docker_boostrap
-  script:
-    - curl --location --output /usr/local/bin/phpunit https://phar.phpunit.de/phpunit.phar
-    - chmod +x /usr/local/bin/phpunit
-    - phpunit --verbose --configuration phpunit.xml.dist
-  tags:
-    - docker
+    - docker
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3d58049..84ef43f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.4.7 (2020-04-11)
+- Update PHPUnit to 9
+- Start adding return types
+
 ## 1.4.6 (2020-01-10)
 - Switched IF Statement order to prevent excess calls to redis.
 
diff --git a/composer.json b/composer.json
index d4327b8..887fa57 100644
--- a/composer.json
+++ b/composer.json
@@ -1,13 +1,13 @@
 {
 	"name": "idanoo/php-resque",
-	"version": "1.4.6",
+	"version": "1.4.7",
 	"type": "library",
 	"replace": {
 		"chrisboulton/php-resque":  "*",
 		"danhunsaker/php-resque": "*"
 	},
 	"description": "Redis backed library for creating background jobs and processing them later. Based on resque for Ruby. Originally forked from chrisboulton/php-resque.",
-	"keywords": ["job", "background", "redis", "resque"],
+	"keywords": ["job", "background", "redis", "resque", "php"],
 	"homepage": "http://www.github.com/idanoo/php-resque/",
 	"license": "MIT",
 	"authors": [
@@ -24,7 +24,7 @@
 		"colinmollenhour/credis": "^1.10"
 	},
 	"require-dev": {
-		"phpunit/phpunit": "^6"
+		"phpunit/phpunit": "^9"
 	},
 	"bin": [
 		"bin/resque"
diff --git a/lib/Resque.php b/lib/Resque.php
index 68b0067..49770e4 100644
--- a/lib/Resque.php
+++ b/lib/Resque.php
@@ -10,7 +10,7 @@
 
 class Resque
 {
-    const VERSION = '1.4.6';
+    const VERSION = '1.4.7';
 
     const DEFAULT_INTERVAL = 5;
 
@@ -51,6 +51,7 @@ class Resque
      * Return an instance of the Resque_Redis class instantiated for Resque.
      *
      * @return Resque_Redis Instance of Resque_Redis.
+     *
      * @throws Resque_RedisException
      */
     public static function redis()
@@ -101,9 +102,10 @@ class Resque
      *
      * @param string $queue The name of the queue to add the job to.
      * @param array $item Job description as an array to be JSON encoded.
+     *
      * @return bool
      */
-    public static function push($queue, $item)
+    public static function push($queue, $item): bool
     {
         $encodedItem = json_encode($item);
         if ($encodedItem === false) {
@@ -122,6 +124,7 @@ class Resque
      * return it.
      *
      * @param string $queue The name of the queue to fetch an item from.
+     *
      * @return mixed Decoded item from the queue.
      */
     public static function pop($queue)
@@ -142,7 +145,7 @@ class Resque
      * @param array $items
      * @return integer number of deleted items
      */
-    public static function dequeue($queue, $items = Array())
+    public static function dequeue($queue, $items = [])
     {
         if (count($items) > 0) {
             return self::removeItems($queue, $items);
@@ -155,13 +158,14 @@ class Resque
      * Remove specified queue
      *
      * @param string $queue The name of the queue to remove.
-     * @return integer Number of deleted items
+     *
+     * @return int Number of deleted items
      */
-    public static function removeQueue($queue)
+    public static function removeQueue($queue): int
     {
         $num = self::removeList($queue);
         self::redis()->srem('queues', $queue);
-        return $num;
+        return intval($num);
     }
 
     /**
@@ -170,12 +174,13 @@ class Resque
      *
      * @param array $queues
      * @param int $timeout
+     *
      * @return array|null|void
      */
     public static function blpop(array $queues, $timeout)
     {
         $list = array();
-        foreach ($queues AS $queue) {
+        foreach ($queues as $queue) {
             $list[] = 'queue:' . $queue;
         }
 
@@ -192,10 +197,10 @@ class Resque
          */
         $queue = substr($item[0], strlen(self::redis()->getPrefix() . 'queue:'));
 
-        return array(
+        return [
             'queue' => $queue,
             'payload' => json_decode($item[1], true)
-        );
+        ];
     }
 
     /**
@@ -205,9 +210,9 @@ class Resque
      *
      * @return int The size of the queue.
      */
-    public static function size($queue)
+    public static function size($queue): int
     {
-        return self::redis()->llen('queue:' . $queue);
+        return intval(self::redis()->llen('queue:' . $queue));
     }
 
     /**
@@ -245,6 +250,7 @@ class Resque
      * Reserve and return the next available job in the specified queue.
      *
      * @param string $queue Queue to fetch next available job from.
+     *
      * @return false|object|Resque_Job
      */
     public static function reserve($queue)
@@ -257,13 +263,10 @@ class Resque
      *
      * @return array Array of queues.
      */
-    public static function queues()
+    public static function queues(): array
     {
         $queues = self::redis()->smembers('queues');
-        if (!is_array($queues)) {
-            $queues = array();
-        }
-        return $queues;
+        return is_array($queues) ? $queues : [];
     }
 
     /**
@@ -276,9 +279,10 @@ class Resque
      *
      * @param string $queue The name of the queue
      * @param array $items
-     * @return integer number of deleted items
+     *
+     * @return int number of deleted items
      */
-    private static function removeItems($queue, $items = Array())
+    private static function removeItems($queue, $items = []): int
     {
         $counter = 0;
         $originalQueue = 'queue:' . $queue;
diff --git a/test/Resque/Tests/EventTest.php b/test/Resque/Tests/EventTest.php
index 24a83c7..2bb4f40 100644
--- a/test/Resque/Tests/EventTest.php
+++ b/test/Resque/Tests/EventTest.php
@@ -13,7 +13,7 @@ class Resque_Tests_EventTest extends Resque_Tests_TestCase
     private $callbacksHit = [];
     private $worker;
 
-    public function setUp()
+    public function setUp(): void
     {
         Test_Job::$called = false;
 
@@ -23,7 +23,7 @@ class Resque_Tests_EventTest extends Resque_Tests_TestCase
         $this->worker->registerWorker();
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         Resque_Event::clearListeners();
         $this->callbacksHit = [];
diff --git a/test/Resque/Tests/JobStatusTest.php b/test/Resque/Tests/JobStatusTest.php
index d573456..3cb0ca8 100644
--- a/test/Resque/Tests/JobStatusTest.php
+++ b/test/Resque/Tests/JobStatusTest.php
@@ -15,7 +15,7 @@ class Resque_Tests_JobStatusTest extends Resque_Tests_TestCase
      */
     protected $worker;
 
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
 
diff --git a/test/Resque/Tests/JobTest.php b/test/Resque/Tests/JobTest.php
index ada26cb..67865f8 100644
--- a/test/Resque/Tests/JobTest.php
+++ b/test/Resque/Tests/JobTest.php
@@ -12,7 +12,7 @@ class Resque_Tests_JobTest extends Resque_Tests_TestCase
 {
     protected $worker;
 
-    public function setUp()
+    public function setUp(): void
     {
         parent::setUp();
 
@@ -44,7 +44,9 @@ class Resque_Tests_JobTest extends Resque_Tests_TestCase
      */
     public function testObjectArgumentsCannotBePassedToJob()
     {
-        $args = new stdClass;
+        $this->expectException(InvalidArgumentException::class);
+
+        $args = new stdClass();
         $args->test = 'somevalue';
         Resque::enqueue('jobs', 'Test_Job', $args);
     }
@@ -121,6 +123,7 @@ class Resque_Tests_JobTest extends Resque_Tests_TestCase
      */
     public function testJobWithoutPerformMethodThrowsException()
     {
+        $this->expectException(Resque_Exception::class);
         Resque::enqueue('jobs', 'Test_Job_Without_Perform_Method');
         $job = $this->worker->reserve();
         $job->worker = $this->worker;
@@ -132,6 +135,7 @@ class Resque_Tests_JobTest extends Resque_Tests_TestCase
      */
     public function testInvalidJobThrowsException()
     {
+        $this->expectException(Resque_Exception::class);
         Resque::enqueue('jobs', 'Invalid_Job');
         $job = $this->worker->reserve();
         $job->worker = $this->worker;
@@ -334,7 +338,7 @@ class Resque_Tests_JobTest extends Resque_Tests_TestCase
         $this->assertEquals($removedItems, 2);
         $this->assertEquals(Resque::size($queue), 1);
         $item = Resque::pop($queue);
-        $this->assertInternalType('array', $item['args']);
+        $this->assertIsArray($item['args']);
         $this->assertEquals(10, $item['args'][0]['bar'], 'Wrong items were dequeued from queue!');
     }
 
diff --git a/test/Resque/Tests/RedisTest.php b/test/Resque/Tests/RedisTest.php
index 7e9a346..2f73bc4 100644
--- a/test/Resque/Tests/RedisTest.php
+++ b/test/Resque/Tests/RedisTest.php
@@ -181,12 +181,14 @@ class Resque_Tests_RedisTest extends Resque_Tests_TestCase
 
     /**
      * @dataProvider bogusDsnStringProvider
+     *
      * @expectedException InvalidArgumentException
+     *
      * @param $dsn
      */
     public function testParsingBogusDsnStringThrowsException($dsn)
     {
-        // The next line should throw an InvalidArgumentException
+        $this->expectException(InvalidArgumentException::class);
         Resque_Redis::parseDsn($dsn);
     }
 }
\ No newline at end of file
diff --git a/test/Resque/Tests/TestCase.php b/test/Resque/Tests/TestCase.php
index a428d12..0e93578 100644
--- a/test/Resque/Tests/TestCase.php
+++ b/test/Resque/Tests/TestCase.php
@@ -13,12 +13,12 @@ class Resque_Tests_TestCase extends PHPUnit\Framework\TestCase
     protected $resque;
     protected $redis;
 
-    public static function setUpBeforeClass()
+    public static function setUpBeforeClass(): void
     {
         date_default_timezone_set('UTC');
     }
 
-    public function setUp()
+    public function setUp(): void
     {
         // Setup redis connection for testing.
         global $redisTestServer;