diff --git a/composer.json b/composer.json
index 20324f6..58025e9 100644
--- a/composer.json
+++ b/composer.json
@@ -11,12 +11,12 @@
         }
     ],
     "require": {
-        "php": "^7.1.3",
+        "php": "^8.1.0",
         "ext-dom": "*",
-        "symfony/expression-language": "~3.4|~4.0|~5.0"
+        "symfony/expression-language": "~3.4|~4.0|~5.0|~6.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "~6.5"
+        "phpunit/phpunit": "~10.0"
     },
     "autoload": {
         "psr-4": {
diff --git a/phpunit.xml b/phpunit.xml
index c9dd1dc..fdc1f96 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,19 +1,14 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:noNamespaceSchemaLocation="phpunit.xsd"
-         bootstrap="tests/bootstrap.php"
-         backupGlobals="false"
-         verbose="true"
-         colors="true">
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.1/phpunit.xsd" bootstrap="tests/bootstrap.php" backupGlobals="false" colors="true" cacheDirectory=".phpunit.cache">
+  <coverage/>
   <testsuites>
     <testsuite name="Test Suite">
       <directory suffix="Test.php">./tests</directory>
     </testsuite>
   </testsuites>
-
-  <filter>
-    <whitelist>
+  <source>
+    <include>
       <directory>./src</directory>
-    </whitelist>
-  </filter>
+    </include>
+  </source>
 </phpunit>
diff --git a/tests/Workflow/ProcessInstanceTest.php b/tests/Workflow/ProcessInstanceTest.php
index 319f504..0b5df00 100644
--- a/tests/Workflow/ProcessInstanceTest.php
+++ b/tests/Workflow/ProcessInstanceTest.php
@@ -30,7 +30,7 @@ class ProcessInstanceTest extends TestCase
     /**
      * {@inheritdoc}
      */
-    protected function setUp()
+    protected function setUp(): void
     {
         $this->workflowRepository = new WorkflowRepository();
     }
@@ -153,7 +153,7 @@ public function completeWorkItem()
     /**
      * @return array
      */
-    public function completeActivityOnConditionalSequenceFlowsData()
+    public static function completeActivityOnConditionalSequenceFlowsData()
     {
         return [
             [true, null],
@@ -196,7 +196,7 @@ public function completeActivityOnConditionalSequenceFlow($rejected, $nextFlowOb
     /**
      * @return array
      */
-    public function selectSequenceFlowOnExclusiveGatewayData()
+    public static function selectSequenceFlowOnExclusiveGatewayData()
     {
         return [
             [true, 'InformRejection'],
@@ -400,9 +400,7 @@ public function executeServiceTasks()
     {
         $participant = $this->createMock(ParticipantInterface::class);
         $participant->method('hasRole')->willReturn(true);
-        $operationRunner = $this->getMockBuilder(OperationRunnerInterface::class)
-            ->setMethods(['provideParticipant', 'run'])
-            ->getMock();
+        $operationRunner = $this->createMock(OperationRunnerInterface::class);
         $operationRunner->method('provideParticipant')->willReturn($participant);
         $self = $this;
         $operationRunner->expects($this->exactly(2))->method('run')->willReturnCallback(function (WorkItemInterface $workItem) use ($self) {
@@ -428,9 +426,7 @@ public function executeServiceTasks()
      */
     public function provideDefaultRoleForWorkflowWithoutLanes()
     {
-        $participant = $this->getMockBuilder(ParticipantInterface::class)
-            ->setMethods(['hasRole', 'setResource', 'getResource', 'getName', 'getId'])
-            ->getMock();
+        $participant = $this->createMock(ParticipantInterface::class);
         $participant->expects($this->exactly(3))->method('hasRole')->with($this->equalTo(ProcessInstance::DEFAULT_ROLE_ID))->willReturn(true);
 
         $workflow = $this->workflowRepository->findById('NoLanesProcess');
@@ -453,9 +449,7 @@ public function executeSendTasks()
     {
         $participant = $this->createMock(ParticipantInterface::class);
         $participant->method('hasRole')->willReturn(true);
-        $operationRunner = $this->getMockBuilder(OperationRunnerInterface::class)
-            ->setMethods(['provideParticipant', 'run'])
-            ->getMock();
+        $operationRunner = $this->createMock(OperationRunnerInterface::class);
         $operationRunner->method('provideParticipant')->willReturn($participant);
         $self = $this;
         $operationRunner->expects($this->exactly(2))->method('run')->willReturnCallback(function (WorkItemInterface $workItem) use ($self) {
@@ -495,7 +489,7 @@ public function parallelGateway()
         $this->assertThat(count($currentFlowObjects), $this->equalTo(count($concurrentFlowObjects)));
 
         foreach ($currentFlowObjects as $currentFlowObject) {
-            $this->assertThat($concurrentFlowObjects, $this->contains($currentFlowObject->getId()));
+            $this->assertThat($concurrentFlowObjects, $this->containsEqual($currentFlowObject->getId()));
             $this->assertThat(current($currentFlowObject->getToken())->getPreviousFlowObject()->getId(), $this->equalTo('ParallelGateway1'));
 
             unset($concurrentFlowObjects[array_search($currentFlowObject->getId(), $concurrentFlowObjects)]);
@@ -524,11 +518,11 @@ public function parallelGateway()
 
         $concurrentFlowObjects = ['ReceivePayment', 'ShipOrder'];
 
-        $this->assertThat($concurrentFlowObjects, $this->contains($activityLog->get(0)->getActivity()->getId()));
+        $this->assertThat($concurrentFlowObjects, $this->containsEqual($activityLog->get(0)->getActivity()->getId()));
 
         unset($concurrentFlowObjects[array_search($activityLog->get(0)->getActivity()->getId(), $concurrentFlowObjects)]);
 
-        $this->assertThat($concurrentFlowObjects, $this->contains($activityLog->get(1)->getActivity()->getId()));
+        $this->assertThat($concurrentFlowObjects, $this->containsEqual($activityLog->get(1)->getActivity()->getId()));
 
         $this->assertThat($activityLog->get(2)->getActivity()->getId(), $this->equalTo('ArchiveOrder'));
     }
@@ -723,9 +717,7 @@ public function executeParallelUserTasks()
             ['test' => 3],
             ['test' => 4],
         ];
-        $dataProvider = $this->getMockBuilder(DataProviderInterface::class)
-            ->setMethods(['getParallelInstancesData', 'getSequentialInstanceData', 'getSingleInstanceData', 'mergeInstancesData'])
-            ->getMock();
+        $dataProvider = $this->createMock(DataProviderInterface::class);
         $dataProvider->method('getParallelInstancesData')->willReturn($parallelData);
 
         $workflow = $this->workflowRepository->findById('ParallelUserTasks');
@@ -765,9 +757,7 @@ public function executeSequentialUserTasks()
         $participant->method('hasRole')->willReturn(true);
 
         $counter = 0;
-        $dataProvider = $this->getMockBuilder(DataProviderInterface::class)
-            ->setMethods(['getParallelInstancesData', 'getSequentialInstanceData', 'getSingleInstanceData', 'mergeInstancesData'])
-            ->getMock();
+        $dataProvider = $this->createMock(DataProviderInterface::class);
         $dataProvider->method('getSequentialInstanceData')->willReturn(['test' => ++$counter]);
 
         $workflow = $this->workflowRepository->findById('SequentialUserTasks');
@@ -928,11 +918,11 @@ public function inclusiveGateway()
 
         $concurrentFlowObjects = ['ReceiveOrder', 'ShipOrder'];
 
-        $this->assertThat($concurrentFlowObjects, $this->contains($activityLog->get(0)->getActivity()->getId()));
+        $this->assertThat($concurrentFlowObjects, $this->containsEqual($activityLog->get(0)->getActivity()->getId()));
 
         unset($concurrentFlowObjects[array_search($activityLog->get(0)->getActivity()->getId(), $concurrentFlowObjects)]);
 
-        $this->assertThat($concurrentFlowObjects, $this->contains($activityLog->get(1)->getActivity()->getId()));
+        $this->assertThat($concurrentFlowObjects, $this->containsEqual($activityLog->get(1)->getActivity()->getId()));
 
         $this->assertThat($activityLog->get(2)->getActivity()->getId(), $this->equalTo('ArchiveOrder'));
     }
@@ -977,7 +967,7 @@ public function inclusiveGateway2()
 
         $concurrentFlowObjects = ['ShipOrder'];
 
-        $this->assertThat($concurrentFlowObjects, $this->contains($activityLog->get(0)->getActivity()->getId()));
+        $this->assertThat($concurrentFlowObjects, $this->containsEqual($activityLog->get(0)->getActivity()->getId()));
 
         $this->assertThat($activityLog->get(1)->getActivity()->getId(), $this->equalTo('ArchiveOrder'));
     }