diff --git a/application/Espo/ORM/Collection.php b/application/Espo/ORM/Collection.php
index 0f85dc2279..65b2e6d696 100644
--- a/application/Espo/ORM/Collection.php
+++ b/application/Espo/ORM/Collection.php
@@ -33,8 +33,10 @@ use Traversable;
 
 /**
  * A collection of entities.
+ *
+ * @todo Extend from Traversable once the min suppoted PHP version is 7.4.
  */
-interface Collection extends Traversable
+interface Collection/* extends Traversable*/
 {
     /**
      * Get an array of StdClass objects.
diff --git a/tests/unit/Espo/Core/Mail/ImporterTest.php b/tests/unit/Espo/Core/Mail/ImporterTest.php
index ff4416c65b..6e33db5c7a 100644
--- a/tests/unit/Espo/Core/Mail/ImporterTest.php
+++ b/tests/unit/Espo/Core/Mail/ImporterTest.php
@@ -43,22 +43,24 @@ class ImporterTest extends \PHPUnit\Framework\TestCase
 
         $config = $this->config = $this->getMockBuilder('Espo\\Core\\Utils\\Config')->disableOriginalConstructor()->getMock();
 
-        $emailRepository = $this->getMockBuilder('Espo\\Core\\ORM\\Repositories\\RDB')->disableOriginalConstructor()->getMock();
-        $emptyRepository = $this->getMockBuilder('Espo\\Core\\ORM\\Repositories\\RDB')->disableOriginalConstructor()->getMock();
+        $emailRepository = $this->getMockBuilder('Espo\\Core\\Repositories\\Database')->disableOriginalConstructor()->getMock();
+        $emptyRepository = $this->getMockBuilder('Espo\\Core\\Repositories\\Database')->disableOriginalConstructor()->getMock();
 
         $metadata = $this->getMockBuilder('Espo\\ORM\\Metadata')->disableOriginalConstructor()->getMock();
 
-        $pdo = $this->getMockBuilder('\\Pdo')->disableOriginalConstructor()->getMock();
+        $pdo = $this->getMockBuilder('Pdo')->disableOriginalConstructor()->getMock();
+
+        $selectBuilder = $this->getMockBuilder('Espo\\ORM\\Repository\\RDBSelectBuilder')->disableOriginalConstructor()->getMock();
 
         $emailRepository
             ->expects($this->any())
             ->method('where')
-            ->will($this->returnSelf());
+            ->will($this->returnValue($selectBuilder));
 
         $emailRepository
             ->expects($this->any())
             ->method('select')
-            ->will($this->returnSelf());
+            ->will($this->returnValue($selectBuilder));
 
         $entityManager
             ->expects($this->any())
@@ -78,14 +80,14 @@ class ImporterTest extends \PHPUnit\Framework\TestCase
         $emptyRepository
             ->expects($this->any())
             ->method('where')
-            ->will($this->returnSelf());
+            ->will($this->returnValue($selectBuilder));
 
-        $this->repositoryMap = array(
-             array('Email', $emailRepository),
-             array('Account', $emptyRepository),
-             array('Contact', $emptyRepository),
-             array('Lead', $emptyRepository)
-        );
+        $this->repositoryMap = [
+             ['Email', $emailRepository],
+             ['Account', $emptyRepository],
+             ['Contact', $emptyRepository],
+             ['Lead', $emptyRepository],
+        ];
 
         $email = $this->email = new Email('Email', [], $entityManager);
 
diff --git a/tests/unit/Espo/Core/Upgrades/ActionManagerTest.php b/tests/unit/Espo/Core/Upgrades/ActionManagerTest.php
index 1954d333bf..2f9d4ad845 100644
--- a/tests/unit/Espo/Core/Upgrades/ActionManagerTest.php
+++ b/tests/unit/Espo/Core/Upgrades/ActionManagerTest.php
@@ -33,6 +33,8 @@ use tests\unit\ReflectionHelper,
     Espo\Core\ExtensionManager,
     Espo\Core\UpgradeManager;
 
+use Espo\Core\Utils\File\Manager as FileManager;
+
 class ActionManagerTest extends \PHPUnit\Framework\TestCase
 {
     protected $object;
@@ -56,9 +58,23 @@ class ActionManagerTest extends \PHPUnit\Framework\TestCase
 
     protected function setUp() : void
     {
-        $this->objects['container'] = $this->getMockBuilder('\Espo\Core\Container')->disableOriginalConstructor()->getMock();
+        $this->objects['container'] =
+            $container = $this->getMockBuilder('Espo\Core\Container')->disableOriginalConstructor()->getMock();
 
-        $this->object = new \Espo\Core\Upgrades\ActionManager($this->params['name'], $this->objects['container'], $this->params['params'] );
+        $fileManager = $this->getMockBuilder(FileManager::class)->disableOriginalConstructor()->getMock();
+
+        $container
+            ->expects($this->any())
+            ->method('get')
+            ->will(
+                $this->returnValueMap([
+                    ['fileManager', $fileManager],
+                ])
+            );
+
+        $this->object = new \Espo\Core\Upgrades\ActionManager(
+            $this->params['name'], $this->objects['container'], $this->params['params']
+        );
 
         $this->reflection = new ReflectionHelper($this->object);
     }