diff --git a/src/pocketmine/entity/Effect.php b/src/pocketmine/entity/Effect.php
index 96299d3ca2..247a7f91ec 100644
--- a/src/pocketmine/entity/Effect.php
+++ b/src/pocketmine/entity/Effect.php
@@ -195,7 +195,8 @@ class Effect{
 	}
 
 	/**
-	 * Returns the default duration this effect will apply for if a duration is not specified.
+	 * Returns the default duration (in ticks) this effect will apply for if a duration is not specified.
+	 *
 	 * @return int
 	 */
 	public function getDefaultDuration() : int{
diff --git a/src/pocketmine/entity/EffectInstance.php b/src/pocketmine/entity/EffectInstance.php
index c66341926a..42475a5c8d 100644
--- a/src/pocketmine/entity/EffectInstance.php
+++ b/src/pocketmine/entity/EffectInstance.php
@@ -75,6 +75,8 @@ class EffectInstance{
 	}
 
 	/**
+	 * Returns the number of ticks remaining until the effect expires.
+	 *
 	 * @return int
 	 */
 	public function getDuration() : int{
@@ -82,6 +84,8 @@ class EffectInstance{
 	}
 
 	/**
+	 * Sets the number of ticks remaining until the effect expires.
+	 *
 	 * @param int $duration
 	 *
 	 * @throws \InvalidArgumentException