diff --git a/DependencyInjection/Configuration.php b/DependencyInjection/Configuration.php
index db809e5..8658bf1 100644
--- a/DependencyInjection/Configuration.php
+++ b/DependencyInjection/Configuration.php
@@ -2,7 +2,6 @@
 
 namespace Lexik\Bundle\FormFilterBundle\DependencyInjection;
 
-use Lexik\Bundle\FormFilterBundle\Filter\FilterOperands;
 use Symfony\Component\Config\Definition\Builder\TreeBuilder;
 use Symfony\Component\Config\Definition\ConfigurationInterface;
 
diff --git a/Event/ApplyFilterConditionEvent.php b/Event/ApplyFilterConditionEvent.php
index 05d24c0..0187fac 100644
--- a/Event/ApplyFilterConditionEvent.php
+++ b/Event/ApplyFilterConditionEvent.php
@@ -3,7 +3,6 @@
 namespace Lexik\Bundle\FormFilterBundle\Event;
 
 use Lexik\Bundle\FormFilterBundle\Filter\Condition\ConditionBuilderInterface;
-use Symfony\Component\EventDispatcher\Event;
 
 /**
  * Event class to compute the WHERE clause from the conditions.
diff --git a/Event/Event.php b/Event/Event.php
new file mode 100644
index 0000000..3c4b192
--- /dev/null
+++ b/Event/Event.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Lexik\Bundle\FormFilterBundle\Event;
+
+use Symfony\Component\EventDispatcher\Event as LegacyEvent;
+use Symfony\Contracts\EventDispatcher\Event as ContractsEvent;
+
+if (\class_exists(ContractsEvent::class)) {
+    abstract class Event extends ContractsEvent
+    {
+    }
+} else {
+    abstract class Event extends LegacyEvent
+    {
+    }
+}
diff --git a/Event/GetFilterConditionEvent.php b/Event/GetFilterConditionEvent.php
index 16e06b0..9a28014 100644
--- a/Event/GetFilterConditionEvent.php
+++ b/Event/GetFilterConditionEvent.php
@@ -2,7 +2,6 @@
 
 namespace Lexik\Bundle\FormFilterBundle\Event;
 
-use Symfony\Component\EventDispatcher\Event;
 use Lexik\Bundle\FormFilterBundle\Filter\Condition\Condition;
 use Lexik\Bundle\FormFilterBundle\Filter\Condition\ConditionInterface;
 use Lexik\Bundle\FormFilterBundle\Filter\Query\QueryInterface;
diff --git a/Event/PrepareEvent.php b/Event/PrepareEvent.php
index e78cbf1..a5f08fc 100644
--- a/Event/PrepareEvent.php
+++ b/Event/PrepareEvent.php
@@ -2,7 +2,6 @@
 
 namespace Lexik\Bundle\FormFilterBundle\Event;
 
-use Symfony\Component\EventDispatcher\Event;
 use Lexik\Bundle\FormFilterBundle\Filter\Query\QueryInterface;
 
 /**
diff --git a/Filter/FilterBuilderUpdater.php b/Filter/FilterBuilderUpdater.php
index 66c927e..f852f81 100644
--- a/Filter/FilterBuilderUpdater.php
+++ b/Filter/FilterBuilderUpdater.php
@@ -6,6 +6,7 @@
 use Symfony\Component\Form\Form;
 use Symfony\Component\Form\FormInterface;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Symfony\Contracts\EventDispatcher\EventDispatcherInterface as ContractsEventDispatcherInterface;
 use Lexik\Bundle\FormFilterBundle\Filter\Condition\ConditionBuilder;
 use Lexik\Bundle\FormFilterBundle\Filter\Condition\ConditionBuilderInterface;
 use Lexik\Bundle\FormFilterBundle\Filter\Condition\ConditionInterface;
@@ -85,7 +86,7 @@ public function addFilterConditions(FormInterface $form, $queryBuilder, $alias =
     {
         // create the right QueryInterface object
         $event = new PrepareEvent($queryBuilder);
-        $this->dispatcher->dispatch(FilterEvents::PREPARE, $event);
+        $this->dispatch(FilterEvents::PREPARE, $event);
 
         if (!$event->getFilterQuery() instanceof QueryInterface) {
             throw new \RuntimeException("Couldn't find any filter query object.");
@@ -103,7 +104,7 @@ public function addFilterConditions(FormInterface $form, $queryBuilder, $alias =
 
         // walk condition nodes to add condition on the query builder instance
         $name = sprintf('lexik_filter.apply_filters.%s', $event->getFilterQuery()->getEventPartName());
-        $this->dispatcher->dispatch($name, new ApplyFilterConditionEvent($queryBuilder, $this->conditionBuilder));
+        $this->dispatch($name, new ApplyFilterConditionEvent($queryBuilder, $this->conditionBuilder));
 
         $this->conditionBuilder = null;
 
@@ -207,7 +208,7 @@ protected function getFilterCondition(FormInterface $form, AbstractType $formTyp
             }
 
             $event = new GetFilterConditionEvent($filterQuery, $field, $values);
-            $this->dispatcher->dispatch($eventName, $event);
+            $this->dispatch($eventName, $event);
 
             $condition = $event->getCondition();
         }
@@ -288,4 +289,21 @@ protected function buildDefaultConditionNode(Form $form, ConditionNodeInterface
             }
         }
     }
+
+    /**
+     * @param string $eventName
+     * @param object $event
+     *
+     * @return mixed
+     */
+    protected function dispatch($eventName, $event)
+    {
+        if ($this->dispatcher instanceof ContractsEventDispatcherInterface) {
+            // Event dispatcher 4.3+
+            return $this->dispatcher->dispatch($event, $eventName);
+        } else {
+            // Event dispatcher < 4.3
+            return $this->dispatcher->dispatch($eventName, $event);
+        }
+    }
 }