diff --git a/src/main/java/org/bukkit/attribute/AttributeModifier.java b/src/main/java/org/bukkit/attribute/AttributeModifier.java
index 2a7ac892..6ffc8951 100644
--- a/src/main/java/org/bukkit/attribute/AttributeModifier.java
+++ b/src/main/java/org/bukkit/attribute/AttributeModifier.java
@@ -7,6 +7,7 @@ import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
 import java.util.UUID;
+import java.util.regex.Pattern;
 import org.bukkit.Keyed;
 import org.bukkit.NamespacedKey;
 import org.bukkit.configuration.serialization.ConfigurationSerializable;
@@ -21,27 +22,28 @@ import org.jetbrains.annotations.Nullable;
  */
 public class AttributeModifier implements ConfigurationSerializable, Keyed {
 
+    private static final Pattern UUID_PATTERN = Pattern.compile("^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$");
     private final NamespacedKey key;
     private final double amount;
     private final Operation operation;
     private final EquipmentSlotGroup slot;
 
-    @Deprecated
+    @Deprecated(since = "1.21", forRemoval = true)
     public AttributeModifier(@NotNull String name, double amount, @NotNull Operation operation) {
         this(UUID.randomUUID(), name, amount, operation);
     }
 
-    @Deprecated
+    @Deprecated(since = "1.21", forRemoval = true)
     public AttributeModifier(@NotNull UUID uuid, @NotNull String name, double amount, @NotNull Operation operation) {
         this(uuid, name, amount, operation, (EquipmentSlot) null);
     }
 
-    @Deprecated
+    @Deprecated(since = "1.21", forRemoval = true)
     public AttributeModifier(@NotNull UUID uuid, @NotNull String name, double amount, @NotNull Operation operation, @Nullable EquipmentSlot slot) {
         this(uuid, name, amount, operation, (slot) == null ? EquipmentSlotGroup.ANY : slot.getGroup());
     }
 
-    @Deprecated
+    @Deprecated(since = "1.21", forRemoval = true)
     public AttributeModifier(@NotNull UUID uuid, @NotNull String name, double amount, @NotNull Operation operation, @NotNull EquipmentSlotGroup slot) {
         this(NamespacedKey.fromString(uuid.toString()), amount, operation, slot);
     }
@@ -64,9 +66,18 @@ public class AttributeModifier implements ConfigurationSerializable, Keyed {
      * @deprecated attributes are now identified by keys
      */
     @NotNull
-    @Deprecated
+    @Deprecated(since = "1.21", forRemoval = true)
     public UUID getUniqueId() {
-        return UUID.nameUUIDFromBytes(getKey().toString().getBytes(StandardCharsets.UTF_8));
+        NamespacedKey namespacedKey = getKey();
+        if (namespacedKey.getNamespace().equals(NamespacedKey.MINECRAFT)) {
+            String key = namespacedKey.getKey();
+
+            if (key.length() == 36 && UUID_PATTERN.matcher(key).matches()) {
+                return UUID.fromString(key);
+            }
+        }
+
+        return UUID.nameUUIDFromBytes(namespacedKey.toString().getBytes(StandardCharsets.UTF_8));
     }
 
     @NotNull