diff --git a/src/event/HandlerList.php b/src/event/HandlerList.php
index 6d391215f..c6ffbaac6 100644
--- a/src/event/HandlerList.php
+++ b/src/event/HandlerList.php
@@ -49,9 +49,6 @@ class HandlerList{
 	 * @throws \Exception
 	 */
 	public function register(RegisteredListener $listener) : void{
-		if(!in_array($listener->getPriority(), EventPriority::ALL, true)){
-			return;
-		}
 		if(isset($this->handlerSlots[$listener->getPriority()][spl_object_id($listener)])){
 			throw new \InvalidStateException("This listener is already registered to priority {$listener->getPriority()} of event {$this->class}");
 		}
diff --git a/src/event/RegisteredListener.php b/src/event/RegisteredListener.php
index 0026063fe..ac06cd652 100644
--- a/src/event/RegisteredListener.php
+++ b/src/event/RegisteredListener.php
@@ -25,6 +25,7 @@ namespace pocketmine\event;
 
 use pocketmine\plugin\Plugin;
 use pocketmine\timings\TimingsHandler;
+use function in_array;
 
 class RegisteredListener{
 
@@ -52,6 +53,9 @@ class RegisteredListener{
 	 * @param TimingsHandler $timings
 	 */
 	public function __construct(\Closure $handler, int $priority, Plugin $plugin, bool $handleCancelled, TimingsHandler $timings){
+		if(!in_array($priority, EventPriority::ALL, true)){
+			throw new \InvalidArgumentException("Invalid priority number $priority");
+		}
 		$this->handler = $handler;
 		$this->priority = $priority;
 		$this->plugin = $plugin;