diff --git a/protocol/src/main/java/org/geysermc/mcprotocollib/protocol/data/game/item/component/MobEffectDetails.java b/protocol/src/main/java/org/geysermc/mcprotocollib/protocol/data/game/item/component/MobEffectDetails.java
index af918f23..2f6e32ef 100644
--- a/protocol/src/main/java/org/geysermc/mcprotocollib/protocol/data/game/item/component/MobEffectDetails.java
+++ b/protocol/src/main/java/org/geysermc/mcprotocollib/protocol/data/game/item/component/MobEffectDetails.java
@@ -2,13 +2,14 @@ package org.geysermc.mcprotocollib.protocol.data.game.item.component;
 
 import lombok.AllArgsConstructor;
 import lombok.Data;
+import lombok.NonNull;
 import org.geysermc.mcprotocollib.protocol.data.game.entity.Effect;
 import org.jetbrains.annotations.Nullable;
 
 @Data
 @AllArgsConstructor
 public class MobEffectDetails {
-    private final Effect effect;
+    private final @NonNull Effect effect;
     private final int amplifier;
     private final int duration;
     private final boolean ambient;