diff --git a/src/main/java/org/bukkit/UnsafeValues.java b/src/main/java/org/bukkit/UnsafeValues.java
index ce9bb54a..96014f53 100644
--- a/src/main/java/org/bukkit/UnsafeValues.java
+++ b/src/main/java/org/bukkit/UnsafeValues.java
@@ -82,6 +82,7 @@ public interface UnsafeValues {
      */
     boolean removeAdvancement(NamespacedKey key);
 
+    @Deprecated(since = "1.21", forRemoval = true)
     Multimap<Attribute, AttributeModifier> getDefaultAttributeModifiers(Material material, EquipmentSlot slot);
 
     CreativeCategory getCreativeCategory(Material material);