diff --git a/src/pocketmine/command/defaults/EffectCommand.php b/src/pocketmine/command/defaults/EffectCommand.php
index a13967bd1..e036021a3 100644
--- a/src/pocketmine/command/defaults/EffectCommand.php
+++ b/src/pocketmine/command/defaults/EffectCommand.php
@@ -83,7 +83,7 @@ class EffectCommand extends VanillaCommand{
 		$amplification = 0;
 
 		if(count($args) >= 3){
-			if(($d = $this->getBoundedInt($sender, $args[2], 0, INT32_MAX)) === null){
+			if(($d = $this->getBoundedInt($sender, $args[2], 0, (int) (INT32_MAX / 20))) === null){
 				return false;
 			}
 			$duration = $d * 20; //ticks