diff --git a/Debug/TraceableEventDispatcher.php b/Debug/TraceableEventDispatcher.php
index f6b96bf..72ce526 100644
--- a/Debug/TraceableEventDispatcher.php
+++ b/Debug/TraceableEventDispatcher.php
@@ -76,7 +76,7 @@ public function removeSubscriber(EventSubscriberInterface $subscriber): void
         $this->dispatcher->removeSubscriber($subscriber);
     }
 
-    public function getListeners(string $eventName = null): array
+    public function getListeners(?string $eventName = null): array
     {
         return $this->dispatcher->getListeners($eventName);
     }
@@ -96,12 +96,12 @@ public function getListenerPriority(string $eventName, callable|array $listener)
         return $this->dispatcher->getListenerPriority($eventName, $listener);
     }
 
-    public function hasListeners(string $eventName = null): bool
+    public function hasListeners(?string $eventName = null): bool
     {
         return $this->dispatcher->hasListeners($eventName);
     }
 
-    public function dispatch(object $event, string $eventName = null): object
+    public function dispatch(object $event, ?string $eventName = null): object
     {
         $eventName ??= $event::class;
 
@@ -136,7 +136,7 @@ public function dispatch(object $event, string $eventName = null): object
         return $event;
     }
 
-    public function getCalledListeners(Request $request = null): array
+    public function getCalledListeners(?Request $request = null): array
     {
         if (null === $this->callStack) {
             return [];
@@ -154,7 +154,7 @@ public function getCalledListeners(Request $request = null): array
         return $called;
     }
 
-    public function getNotCalledListeners(Request $request = null): array
+    public function getNotCalledListeners(?Request $request = null): array
     {
         try {
             $allListeners = $this->dispatcher instanceof EventDispatcher ? $this->getListenersWithPriority() : $this->getListenersWithoutPriority();
@@ -196,7 +196,7 @@ public function getNotCalledListeners(Request $request = null): array
         return $notCalled;
     }
 
-    public function getOrphanedEvents(Request $request = null): array
+    public function getOrphanedEvents(?Request $request = null): array
     {
         if ($request) {
             return $this->orphanedEvents[spl_object_hash($request)] ?? [];
diff --git a/EventDispatcher.php b/EventDispatcher.php
index 65d8626..43bc16b 100644
--- a/EventDispatcher.php
+++ b/EventDispatcher.php
@@ -42,7 +42,7 @@ public function __construct()
         }
     }
 
-    public function dispatch(object $event, string $eventName = null): object
+    public function dispatch(object $event, ?string $eventName = null): object
     {
         $eventName ??= $event::class;
 
@@ -59,7 +59,7 @@ public function dispatch(object $event, string $eventName = null): object
         return $event;
     }
 
-    public function getListeners(string $eventName = null): array
+    public function getListeners(?string $eventName = null): array
     {
         if (null !== $eventName) {
             if (empty($this->listeners[$eventName])) {
@@ -108,7 +108,7 @@ public function getListenerPriority(string $eventName, callable|array $listener)
         return null;
     }
 
-    public function hasListeners(string $eventName = null): bool
+    public function hasListeners(?string $eventName = null): bool
     {
         if (null !== $eventName) {
             return !empty($this->listeners[$eventName]);
diff --git a/EventDispatcherInterface.php b/EventDispatcherInterface.php
index 6d4a5b4..99f8b1a 100644
--- a/EventDispatcherInterface.php
+++ b/EventDispatcherInterface.php
@@ -50,7 +50,7 @@ public function removeSubscriber(EventSubscriberInterface $subscriber): void;
      *
      * @return array<callable[]|callable>
      */
-    public function getListeners(string $eventName = null): array;
+    public function getListeners(?string $eventName = null): array;
 
     /**
      * Gets the listener priority for a specific event.
@@ -62,5 +62,5 @@ public function getListenerPriority(string $eventName, callable $listener): ?int
     /**
      * Checks whether an event has any registered listeners.
      */
-    public function hasListeners(string $eventName = null): bool;
+    public function hasListeners(?string $eventName = null): bool;
 }
diff --git a/ImmutableEventDispatcher.php b/ImmutableEventDispatcher.php
index f715ecb..a6d078e 100644
--- a/ImmutableEventDispatcher.php
+++ b/ImmutableEventDispatcher.php
@@ -23,7 +23,7 @@ public function __construct(
     ) {
     }
 
-    public function dispatch(object $event, string $eventName = null): object
+    public function dispatch(object $event, ?string $eventName = null): object
     {
         return $this->dispatcher->dispatch($event, $eventName);
     }
@@ -48,7 +48,7 @@ public function removeSubscriber(EventSubscriberInterface $subscriber): never
         throw new \BadMethodCallException('Unmodifiable event dispatchers must not be modified.');
     }
 
-    public function getListeners(string $eventName = null): array
+    public function getListeners(?string $eventName = null): array
     {
         return $this->dispatcher->getListeners($eventName);
     }
@@ -58,7 +58,7 @@ public function getListenerPriority(string $eventName, callable|array $listener)
         return $this->dispatcher->getListenerPriority($eventName, $listener);
     }
 
-    public function hasListeners(string $eventName = null): bool
+    public function hasListeners(?string $eventName = null): bool
     {
         return $this->dispatcher->hasListeners($eventName);
     }