diff --git a/src/pocketmine/entity/Effect.php b/src/pocketmine/entity/Effect.php
index 1f4bbc8fa..3b97c1405 100644
--- a/src/pocketmine/entity/Effect.php
+++ b/src/pocketmine/entity/Effect.php
@@ -22,6 +22,8 @@
 namespace pocketmine\entity;
 
 use pocketmine\event\entity\EntityDamageEvent;
+use pocketmine\event\entity\EntityEffectAddEvent;
+use pocketmine\event\entity\EntityEffectRemoveEvent;
 use pocketmine\event\entity\EntityRegainHealthEvent;
 use pocketmine\event\player\PlayerExhaustEvent;
 use pocketmine\network\protocol\MobEffectPacket;
@@ -251,6 +253,10 @@ class Effect{
 	}
 
 	public function add(Entity $entity, $modify = false, Effect $oldEffect = null){
+		$entity->getLevel()->getServer()->getPluginManager()->callEvent($ev = new EntityEffectAddEvent($entity, $this, $modify, $oldEffect));
+		if($ev->isCancelled()){
+			return;
+		}
 		if($entity instanceof Player){
 			$pk = new MobEffectPacket();
 			$pk->eid = 0;
@@ -258,7 +264,7 @@ class Effect{
 			$pk->amplifier = $this->getAmplifier();
 			$pk->particles = $this->isVisible();
 			$pk->duration = $this->getDuration();
-			if($modify){
+			if($ev->willModify()){
 				$pk->eventId = MobEffectPacket::EVENT_MODIFY;
 			}else{
 				$pk->eventId = MobEffectPacket::EVENT_ADD;
@@ -272,7 +278,7 @@ class Effect{
 			$entity->setNameTagVisible(false);
 		}elseif($this->id === Effect::SPEED){
 			$attr = $entity->getAttributeMap()->getAttribute(Attribute::MOVEMENT_SPEED);
-			if($modify and $oldEffect !== null){
+			if($ev->willModify() and $oldEffect !== null){
 				$speed = $attr->getValue() / (1 + 0.2 * $oldEffect->getAmplifier());
 			}else{
 				$speed = $attr->getValue();
@@ -281,7 +287,7 @@ class Effect{
 			$attr->setValue($speed);
 		}elseif($this->id === Effect::SLOWNESS){
 			$attr = $entity->getAttributeMap()->getAttribute(Attribute::MOVEMENT_SPEED);
-			if($modify and $oldEffect !== null){
+			if($ev->willModify() and $oldEffect !== null){
 				$speed = $attr->getValue() / (1 - 0.15 * $oldEffect->getAmplifier());
 			}else{
 				$speed = $attr->getValue();
@@ -292,6 +298,10 @@ class Effect{
 	}
 
 	public function remove(Entity $entity){
+		$entity->getLevel()->getServer()->getPluginManager()->callEvent($ev = new EntityEffectRemoveEvent($entity, $this));
+		if($ev->isCancelled()){
+			return;
+		}
 		if($entity instanceof Player){
 			$pk = new MobEffectPacket();
 			$pk->eid = 0;
diff --git a/src/pocketmine/event/entity/EntityEffectAddEvent.php b/src/pocketmine/event/entity/EntityEffectAddEvent.php
new file mode 100644
index 000000000..715a1df1f
--- /dev/null
+++ b/src/pocketmine/event/entity/EntityEffectAddEvent.php
@@ -0,0 +1,61 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\event\entity;
+
+use pocketmine\entity\Effect;
+use pocketmine\entity\Entity;
+
+class EntityEffectAddEvent extends EntityEffectEvent{
+	public static $handlerList = null;
+
+	/** @var bool */
+	private $modify;
+	/** @var Effect */
+	private $oldEffect;
+
+	public function __construct(Entity $entity, Effect $effect, $modify, $oldEffect){
+		parent::__construct($entity, $effect);
+		$this->modify = $modify;
+		$this->oldEffect = $oldEffect;
+	}
+
+	public function willModify() : bool{
+		return $this->modify;
+	}
+
+	public function setWillModify(bool $modify){
+		$this->modify = $modify;
+	}
+
+	public function hasOldEffect() : bool{
+		return $this->oldEffect instanceof Effect;
+	}
+
+	/**
+	 * @return Effect|null
+	 */
+	public function getOldEffect(){
+		return $this->oldEffect;
+	}
+
+
+}
\ No newline at end of file
diff --git a/src/pocketmine/event/entity/EntityEffectEvent.php b/src/pocketmine/event/entity/EntityEffectEvent.php
new file mode 100644
index 000000000..55fb1b895
--- /dev/null
+++ b/src/pocketmine/event/entity/EntityEffectEvent.php
@@ -0,0 +1,41 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\event\entity;
+
+use pocketmine\entity\Effect;
+use pocketmine\entity\Entity;
+use pocketmine\event\Cancellable;
+
+class EntityEffectEvent extends EntityEvent implements Cancellable{
+
+	/** @var Effect */
+	private $effect;
+
+	public function __construct(Entity $entity, Effect $effect){
+		$this->entity = $entity;
+		$this->effect = $effect;
+	}
+
+	public function getEffect() : Effect{
+		return $this->effect;
+	}
+}
\ No newline at end of file
diff --git a/src/pocketmine/event/entity/EntityEffectRemoveEvent.php b/src/pocketmine/event/entity/EntityEffectRemoveEvent.php
new file mode 100644
index 000000000..9b0c84475
--- /dev/null
+++ b/src/pocketmine/event/entity/EntityEffectRemoveEvent.php
@@ -0,0 +1,27 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+namespace pocketmine\event\entity;
+
+class EntityEffectRemoveEvent extends EntityEffectEvent{
+	public static $handlerList = null;
+
+}
\ No newline at end of file