diff --git a/minecraft/protocol/entity_metadata.go b/minecraft/protocol/entity_metadata.go
index d96d97c2..cd90203e 100644
--- a/minecraft/protocol/entity_metadata.go
+++ b/minecraft/protocol/entity_metadata.go
@@ -132,6 +132,7 @@ const (
 	EntityDataKeyPlayerLastDeathDimension
 	EntityDataKeyPlayerHasDied
 	EntityDataKeyCollisionBox
+	EntityDataKeyVisibleMobEffects
 )
 
 const (