diff --git a/src/Symfony/Component/Workflow/DefinitionBuilder.php b/src/Symfony/Component/Workflow/DefinitionBuilder.php
index 182376c060..19e9067edd 100644
--- a/src/Symfony/Component/Workflow/DefinitionBuilder.php
+++ b/src/Symfony/Component/Workflow/DefinitionBuilder.php
@@ -73,11 +73,9 @@ class DefinitionBuilder
     }
 
     /**
-     * @param string $place
-     *
      * @return $this
      */
-    public function addPlace($place)
+    public function addPlace(string $place)
     {
         if (!$this->places) {
             $this->initialPlaces = $place;
diff --git a/src/Symfony/Component/Workflow/Dumper/DumperInterface.php b/src/Symfony/Component/Workflow/Dumper/DumperInterface.php
index 797c63e32b..e1d8c7d682 100644
--- a/src/Symfony/Component/Workflow/Dumper/DumperInterface.php
+++ b/src/Symfony/Component/Workflow/Dumper/DumperInterface.php
@@ -25,10 +25,6 @@ interface DumperInterface
     /**
      * Dumps a workflow definition.
      *
-     * @param Definition   $definition A Definition instance
-     * @param Marking|null $marking    A Marking instance
-     * @param array        $options    An array of options
-     *
      * @return string The representation of the workflow
      */
     public function dump(Definition $definition, Marking $marking = null, array $options = []);
diff --git a/src/Symfony/Component/Workflow/Dumper/GraphvizDumper.php b/src/Symfony/Component/Workflow/Dumper/GraphvizDumper.php
index 82034bb7bd..2e518d1dfb 100644
--- a/src/Symfony/Component/Workflow/Dumper/GraphvizDumper.php
+++ b/src/Symfony/Component/Workflow/Dumper/GraphvizDumper.php
@@ -236,7 +236,7 @@ class GraphvizDumper implements DumperInterface
     /**
      * @internal
      */
-    protected function dotize($id)
+    protected function dotize(string $id)
     {
         return hash('sha1', $id);
     }
diff --git a/src/Symfony/Component/Workflow/Event/Event.php b/src/Symfony/Component/Workflow/Event/Event.php
index 65b4533c6f..a0bb4c5176 100644
--- a/src/Symfony/Component/Workflow/Event/Event.php
+++ b/src/Symfony/Component/Workflow/Event/Event.php
@@ -27,10 +27,7 @@ class Event extends BaseEvent
     private $transition;
     private $workflow;
 
-    /**
-     * @param object $subject
-     */
-    public function __construct($subject, Marking $marking, Transition $transition = null, WorkflowInterface $workflow = null)
+    public function __construct(object $subject, Marking $marking, Transition $transition = null, WorkflowInterface $workflow = null)
     {
         $this->subject = $subject;
         $this->marking = $marking;
@@ -63,7 +60,7 @@ class Event extends BaseEvent
         return $this->workflow->getName();
     }
 
-    public function getMetadata(string $key, $subject)
+    public function getMetadata(string $key, object $subject)
     {
         return $this->workflow->getMetadataStore()->getMetadata($key, $subject);
     }
diff --git a/src/Symfony/Component/Workflow/Event/GuardEvent.php b/src/Symfony/Component/Workflow/Event/GuardEvent.php
index 9a7d644964..2004fa6162 100644
--- a/src/Symfony/Component/Workflow/Event/GuardEvent.php
+++ b/src/Symfony/Component/Workflow/Event/GuardEvent.php
@@ -15,6 +15,7 @@ use Symfony\Component\Workflow\Marking;
 use Symfony\Component\Workflow\Transition;
 use Symfony\Component\Workflow\TransitionBlocker;
 use Symfony\Component\Workflow\TransitionBlockerList;
+use Symfony\Component\Workflow\WorkflowInterface;
 
 /**
  * @author Fabien Potencier <fabien@symfony.com>
@@ -27,9 +28,9 @@ class GuardEvent extends Event
     /**
      * {@inheritdoc}
      */
-    public function __construct($subject, Marking $marking, Transition $transition, $workflowName = null)
+    public function __construct(object $subject, Marking $marking, Transition $transition, WorkflowInterface $workflow = null)
     {
-        parent::__construct($subject, $marking, $transition, $workflowName);
+        parent::__construct($subject, $marking, $transition, $workflow);
 
         $this->transitionBlockerList = new TransitionBlockerList();
     }
diff --git a/src/Symfony/Component/Workflow/EventListener/GuardExpression.php b/src/Symfony/Component/Workflow/EventListener/GuardExpression.php
index 09ab15086b..c7ac9cede7 100644
--- a/src/Symfony/Component/Workflow/EventListener/GuardExpression.php
+++ b/src/Symfony/Component/Workflow/EventListener/GuardExpression.php
@@ -16,13 +16,9 @@ use Symfony\Component\Workflow\Transition;
 class GuardExpression
 {
     private $transition;
-
     private $expression;
 
-    /**
-     * @param string $expression
-     */
-    public function __construct(Transition $transition, $expression)
+    public function __construct(Transition $transition, string $expression)
     {
         $this->transition = $transition;
         $this->expression = $expression;
diff --git a/src/Symfony/Component/Workflow/EventListener/GuardListener.php b/src/Symfony/Component/Workflow/EventListener/GuardListener.php
index 25aa67ae1b..4badb75afb 100644
--- a/src/Symfony/Component/Workflow/EventListener/GuardListener.php
+++ b/src/Symfony/Component/Workflow/EventListener/GuardListener.php
@@ -44,7 +44,7 @@ class GuardListener
         $this->validator = $validator;
     }
 
-    public function onTransition(GuardEvent $event, $eventName)
+    public function onTransition(GuardEvent $event, string $eventName)
     {
         if (!isset($this->configuration[$eventName])) {
             return;
diff --git a/src/Symfony/Component/Workflow/Exception/NotEnabledTransitionException.php b/src/Symfony/Component/Workflow/Exception/NotEnabledTransitionException.php
index 738aab8387..7b5b21e724 100644
--- a/src/Symfony/Component/Workflow/Exception/NotEnabledTransitionException.php
+++ b/src/Symfony/Component/Workflow/Exception/NotEnabledTransitionException.php
@@ -23,7 +23,7 @@ class NotEnabledTransitionException extends TransitionException
 {
     private $transitionBlockerList;
 
-    public function __construct($subject, string $transitionName, WorkflowInterface $workflow, TransitionBlockerList $transitionBlockerList)
+    public function __construct(object $subject, string $transitionName, WorkflowInterface $workflow, TransitionBlockerList $transitionBlockerList)
     {
         parent::__construct($subject, $transitionName, $workflow, sprintf('Transition "%s" is not enabled for workflow "%s".', $transitionName, $workflow->getName()));
 
diff --git a/src/Symfony/Component/Workflow/Exception/TransitionException.php b/src/Symfony/Component/Workflow/Exception/TransitionException.php
index d09df40d44..a5ace57487 100644
--- a/src/Symfony/Component/Workflow/Exception/TransitionException.php
+++ b/src/Symfony/Component/Workflow/Exception/TransitionException.php
@@ -23,7 +23,7 @@ class TransitionException extends LogicException
     private $transitionName;
     private $workflow;
 
-    public function __construct($subject, string $transitionName, WorkflowInterface $workflow, string $message)
+    public function __construct(object $subject, string $transitionName, WorkflowInterface $workflow, string $message)
     {
         parent::__construct($message);
 
diff --git a/src/Symfony/Component/Workflow/Exception/UndefinedTransitionException.php b/src/Symfony/Component/Workflow/Exception/UndefinedTransitionException.php
index 6d13ccfa5e..d5d6dab663 100644
--- a/src/Symfony/Component/Workflow/Exception/UndefinedTransitionException.php
+++ b/src/Symfony/Component/Workflow/Exception/UndefinedTransitionException.php
@@ -20,7 +20,7 @@ use Symfony\Component\Workflow\WorkflowInterface;
  */
 class UndefinedTransitionException extends TransitionException
 {
-    public function __construct($subject, string $transitionName, WorkflowInterface $workflow)
+    public function __construct(object $subject, string $transitionName, WorkflowInterface $workflow)
     {
         parent::__construct($subject, $transitionName, $workflow, sprintf('Transition "%s" is not defined for workflow "%s".', $transitionName, $workflow->getName()));
     }
diff --git a/src/Symfony/Component/Workflow/Marking.php b/src/Symfony/Component/Workflow/Marking.php
index 8cb2dbedb8..974a040b0d 100644
--- a/src/Symfony/Component/Workflow/Marking.php
+++ b/src/Symfony/Component/Workflow/Marking.php
@@ -30,17 +30,17 @@ class Marking
         }
     }
 
-    public function mark($place)
+    public function mark(string $place)
     {
         $this->places[$place] = 1;
     }
 
-    public function unmark($place)
+    public function unmark(string $place)
     {
         unset($this->places[$place]);
     }
 
-    public function has($place)
+    public function has(string $place)
     {
         return isset($this->places[$place]);
     }
diff --git a/src/Symfony/Component/Workflow/MarkingStore/MethodMarkingStore.php b/src/Symfony/Component/Workflow/MarkingStore/MethodMarkingStore.php
index df1a6a24ab..5951f5f800 100644
--- a/src/Symfony/Component/Workflow/MarkingStore/MethodMarkingStore.php
+++ b/src/Symfony/Component/Workflow/MarkingStore/MethodMarkingStore.php
@@ -46,7 +46,7 @@ final class MethodMarkingStore implements MarkingStoreInterface
     /**
      * {@inheritdoc}
      */
-    public function getMarking($subject): Marking
+    public function getMarking(object $subject): Marking
     {
         $method = 'get'.ucfirst($this->property);
 
@@ -70,7 +70,7 @@ final class MethodMarkingStore implements MarkingStoreInterface
     /**
      * {@inheritdoc}
      */
-    public function setMarking($subject, Marking $marking, array $context = [])
+    public function setMarking(object $subject, Marking $marking, array $context = [])
     {
         $marking = $marking->getPlaces();
 
diff --git a/src/Symfony/Component/Workflow/Registry.php b/src/Symfony/Component/Workflow/Registry.php
index ffb0732fcb..89199b491a 100644
--- a/src/Symfony/Component/Workflow/Registry.php
+++ b/src/Symfony/Component/Workflow/Registry.php
@@ -28,12 +28,9 @@ class Registry
     }
 
     /**
-     * @param object      $subject
-     * @param string|null $workflowName
-     *
      * @return Workflow
      */
-    public function get($subject, $workflowName = null)
+    public function get(object $subject, string $workflowName = null)
     {
         $matched = null;
 
@@ -54,11 +51,9 @@ class Registry
     }
 
     /**
-     * @param object $subject
-     *
      * @return Workflow[]
      */
-    public function all($subject): array
+    public function all(object $subject): array
     {
         $matched = [];
         foreach ($this->workflows as list($workflow, $supportStrategy)) {
diff --git a/src/Symfony/Component/Workflow/SupportStrategy/InstanceOfSupportStrategy.php b/src/Symfony/Component/Workflow/SupportStrategy/InstanceOfSupportStrategy.php
index 079bf27cbd..487795eca4 100644
--- a/src/Symfony/Component/Workflow/SupportStrategy/InstanceOfSupportStrategy.php
+++ b/src/Symfony/Component/Workflow/SupportStrategy/InstanceOfSupportStrategy.php
@@ -29,7 +29,7 @@ final class InstanceOfSupportStrategy implements WorkflowSupportStrategyInterfac
     /**
      * {@inheritdoc}
      */
-    public function supports(WorkflowInterface $workflow, $subject): bool
+    public function supports(WorkflowInterface $workflow, object $subject): bool
     {
         return $subject instanceof $this->className;
     }
diff --git a/src/Symfony/Component/Workflow/SupportStrategy/WorkflowSupportStrategyInterface.php b/src/Symfony/Component/Workflow/SupportStrategy/WorkflowSupportStrategyInterface.php
index 715c317636..11f01c7300 100644
--- a/src/Symfony/Component/Workflow/SupportStrategy/WorkflowSupportStrategyInterface.php
+++ b/src/Symfony/Component/Workflow/SupportStrategy/WorkflowSupportStrategyInterface.php
@@ -18,5 +18,5 @@ use Symfony\Component\Workflow\WorkflowInterface;
  */
 interface WorkflowSupportStrategyInterface
 {
-    public function supports(WorkflowInterface $workflow, $subject): bool;
+    public function supports(WorkflowInterface $workflow, object $subject): bool;
 }
diff --git a/src/Symfony/Component/Workflow/Validator/DefinitionValidatorInterface.php b/src/Symfony/Component/Workflow/Validator/DefinitionValidatorInterface.php
index 1282c966b7..f02f582074 100644
--- a/src/Symfony/Component/Workflow/Validator/DefinitionValidatorInterface.php
+++ b/src/Symfony/Component/Workflow/Validator/DefinitionValidatorInterface.php
@@ -21,10 +21,7 @@ use Symfony\Component\Workflow\Exception\InvalidDefinitionException;
 interface DefinitionValidatorInterface
 {
     /**
-     * @param Definition $definition
-     * @param string     $name
-     *
      * @throws InvalidDefinitionException on invalid definition
      */
-    public function validate(Definition $definition, $name);
+    public function validate(Definition $definition, string $name);
 }
diff --git a/src/Symfony/Component/Workflow/Validator/StateMachineValidator.php b/src/Symfony/Component/Workflow/Validator/StateMachineValidator.php
index b2a5c83b52..2bb81d21a0 100644
--- a/src/Symfony/Component/Workflow/Validator/StateMachineValidator.php
+++ b/src/Symfony/Component/Workflow/Validator/StateMachineValidator.php
@@ -19,7 +19,7 @@ use Symfony\Component\Workflow\Exception\InvalidDefinitionException;
  */
 class StateMachineValidator implements DefinitionValidatorInterface
 {
-    public function validate(Definition $definition, $name)
+    public function validate(Definition $definition, string $name)
     {
         $transitionFromNames = [];
         foreach ($definition->getTransitions() as $transition) {
diff --git a/src/Symfony/Component/Workflow/Validator/WorkflowValidator.php b/src/Symfony/Component/Workflow/Validator/WorkflowValidator.php
index 5e6df2dd24..32cc80ef1e 100644
--- a/src/Symfony/Component/Workflow/Validator/WorkflowValidator.php
+++ b/src/Symfony/Component/Workflow/Validator/WorkflowValidator.php
@@ -27,7 +27,7 @@ class WorkflowValidator implements DefinitionValidatorInterface
         $this->singlePlace = $singlePlace;
     }
 
-    public function validate(Definition $definition, $name)
+    public function validate(Definition $definition, string $name)
     {
         // Make sure all transitions for one place has unique name.
         $places = array_fill_keys($definition->getPlaces(), []);
diff --git a/src/Symfony/Component/Workflow/Workflow.php b/src/Symfony/Component/Workflow/Workflow.php
index 000fa1c569..3e61ec3779 100644
--- a/src/Symfony/Component/Workflow/Workflow.php
+++ b/src/Symfony/Component/Workflow/Workflow.php
@@ -49,7 +49,7 @@ class Workflow implements WorkflowInterface
     /**
      * {@inheritdoc}
      */
-    public function getMarking($subject)
+    public function getMarking(object $subject)
     {
         $marking = $this->markingStore->getMarking($subject);
 
@@ -91,7 +91,7 @@ class Workflow implements WorkflowInterface
     /**
      * {@inheritdoc}
      */
-    public function can($subject, $transitionName)
+    public function can(object $subject, string $transitionName)
     {
         $transitions = $this->definition->getTransitions();
         $marking = $this->getMarking($subject);
@@ -114,7 +114,7 @@ class Workflow implements WorkflowInterface
     /**
      * {@inheritdoc}
      */
-    public function buildTransitionBlockerList($subject, string $transitionName): TransitionBlockerList
+    public function buildTransitionBlockerList(object $subject, string $transitionName): TransitionBlockerList
     {
         $transitions = $this->definition->getTransitions();
         $marking = $this->getMarking($subject);
@@ -150,7 +150,7 @@ class Workflow implements WorkflowInterface
     /**
      * {@inheritdoc}
      */
-    public function apply($subject, $transitionName, array $context = [])
+    public function apply(object $subject, string $transitionName, array $context = [])
     {
         $marking = $this->getMarking($subject);
 
@@ -202,7 +202,7 @@ class Workflow implements WorkflowInterface
     /**
      * {@inheritdoc}
      */
-    public function getEnabledTransitions($subject)
+    public function getEnabledTransitions(object $subject)
     {
         $enabledTransitions = [];
         $marking = $this->getMarking($subject);
@@ -249,7 +249,7 @@ class Workflow implements WorkflowInterface
         return $this->definition->getMetadataStore();
     }
 
-    private function buildTransitionBlockerListForTransition($subject, Marking $marking, Transition $transition)
+    private function buildTransitionBlockerListForTransition(object $subject, Marking $marking, Transition $transition)
     {
         foreach ($transition->getFroms() as $place) {
             if (!$marking->has($place)) {
@@ -272,7 +272,7 @@ class Workflow implements WorkflowInterface
         return new TransitionBlockerList();
     }
 
-    private function guardTransition($subject, Marking $marking, Transition $transition): ?GuardEvent
+    private function guardTransition(object $subject, Marking $marking, Transition $transition): ?GuardEvent
     {
         if (null === $this->dispatcher) {
             return null;
@@ -287,7 +287,7 @@ class Workflow implements WorkflowInterface
         return $event;
     }
 
-    private function leave($subject, Transition $transition, Marking $marking): void
+    private function leave(object $subject, Transition $transition, Marking $marking): void
     {
         $places = $transition->getFroms();
 
@@ -307,7 +307,7 @@ class Workflow implements WorkflowInterface
         }
     }
 
-    private function transition($subject, Transition $transition, Marking $marking, array $context): array
+    private function transition(object $subject, Transition $transition, Marking $marking, array $context): array
     {
         if (null === $this->dispatcher) {
             return $context;
@@ -323,7 +323,7 @@ class Workflow implements WorkflowInterface
         return $event->getContext();
     }
 
-    private function enter($subject, Transition $transition, Marking $marking): void
+    private function enter(object $subject, Transition $transition, Marking $marking): void
     {
         $places = $transition->getTos();
 
@@ -343,7 +343,7 @@ class Workflow implements WorkflowInterface
         }
     }
 
-    private function entered($subject, Transition $transition = null, Marking $marking): void
+    private function entered(object $subject, ?Transition $transition, Marking $marking): void
     {
         if (null === $this->dispatcher) {
             return;
@@ -361,7 +361,7 @@ class Workflow implements WorkflowInterface
         }
     }
 
-    private function completed($subject, Transition $transition, Marking $marking): void
+    private function completed(object $subject, Transition $transition, Marking $marking): void
     {
         if (null === $this->dispatcher) {
             return;
@@ -374,7 +374,7 @@ class Workflow implements WorkflowInterface
         $this->dispatcher->dispatch($event, sprintf('workflow.%s.completed.%s', $this->name, $transition->getName()));
     }
 
-    private function announce($subject, Transition $initialTransition, Marking $marking): void
+    private function announce(object $subject, Transition $initialTransition, Marking $marking): void
     {
         if (null === $this->dispatcher) {
             return;
diff --git a/src/Symfony/Component/Workflow/WorkflowInterface.php b/src/Symfony/Component/Workflow/WorkflowInterface.php
index d6de18fee5..39d9361a5f 100644
--- a/src/Symfony/Component/Workflow/WorkflowInterface.php
+++ b/src/Symfony/Component/Workflow/WorkflowInterface.php
@@ -23,51 +23,39 @@ interface WorkflowInterface
     /**
      * Returns the object's Marking.
      *
-     * @param object $subject A subject
-     *
      * @return Marking The Marking
      *
      * @throws LogicException
      */
-    public function getMarking($subject);
+    public function getMarking(object $subject);
 
     /**
      * Returns true if the transition is enabled.
      *
-     * @param object $subject        A subject
-     * @param string $transitionName A transition
-     *
      * @return bool true if the transition is enabled
      */
-    public function can($subject, $transitionName);
+    public function can(object $subject, string $transitionName);
 
     /**
      * Builds a TransitionBlockerList to know why a transition is blocked.
-     *
-     * @param object $subject A subject
      */
-    public function buildTransitionBlockerList($subject, string $transitionName): TransitionBlockerList;
+    public function buildTransitionBlockerList(object $subject, string $transitionName): TransitionBlockerList;
 
     /**
      * Fire a transition.
      *
-     * @param object $subject        A subject
-     * @param string $transitionName A transition
-     *
      * @return Marking The new Marking
      *
      * @throws LogicException If the transition is not applicable
      */
-    public function apply($subject, $transitionName, array $context = []);
+    public function apply(object $subject, string $transitionName, array $context = []);
 
     /**
      * Returns all enabled transitions.
      *
-     * @param object $subject A subject
-     *
      * @return Transition[] All enabled transitions
      */
-    public function getEnabledTransitions($subject);
+    public function getEnabledTransitions(object $subject);
 
     /**
      * @return string