diff --git a/src/main/java/net/tfminecraft/magic/artifact/ArtifactCarePlaces.java b/src/main/java/net/tfminecraft/magic/artifact/ArtifactCarePlaces.java
index c8ad919..0ca0501 100644
--- a/src/main/java/net/tfminecraft/magic/artifact/ArtifactCarePlaces.java
+++ b/src/main/java/net/tfminecraft/magic/artifact/ArtifactCarePlaces.java
@@ -19,7 +19,7 @@ public static boolean accepted(Inventory inventory, ItemStack stack) {
         if (ArtifactDisplayIndex.isDisplayed(ArtifactIds.read(stack))) {
             return true;
         }
-        InventoryHolder holder = inventory.getHolder();
+        InventoryHolder holder = inventory.getHolder(false);
         return holder instanceof Player || holder instanceof ItemFrame;
     }
 }
diff --git a/src/main/java/net/tfminecraft/magic/gear/gui/GearInventoryManager.java b/src/main/java/net/tfminecraft/magic/gear/gui/GearInventoryManager.java
index 35a4122..aa685cd 100644
--- a/src/main/java/net/tfminecraft/magic/gear/gui/GearInventoryManager.java
+++ b/src/main/java/net/tfminecraft/magic/gear/gui/GearInventoryManager.java
@@ -13,6 +13,7 @@
 import org.bukkit.event.Listener;
 import org.bukkit.event.inventory.InventoryClickEvent;
 import org.bukkit.inventory.Inventory;
+import org.bukkit.inventory.InventoryHolder;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.ItemMeta;
 import org.bukkit.persistence.PersistentDataType;
@@ -177,10 +178,11 @@ public void onClick(InventoryClickEvent event) {
         if (!(event.getWhoClicked() instanceof Player player)) {
             return;
         }
-        if (event.getInventory().getHolder() instanceof GearMenuHolder holder && !holder.current(player)) {
+        InventoryHolder menu = event.getInventory().getHolder(false);
+        if (menu instanceof GearMenuHolder holder && !holder.current(player)) {
             event.setCancelled(true); return;
         }
-        if (event.getInventory().getHolder() instanceof AssemblyHolder) {
+        if (menu instanceof AssemblyHolder) {
             event.setCancelled(true);
             if (event.getClickedInventory() != event.getInventory()) return;
             ItemStack current = event.getCurrentItem();
@@ -211,7 +213,7 @@ public void onClick(InventoryClickEvent event) {
             }
             return;
         }
-        if (event.getInventory().getHolder() instanceof TypeSelectionHolder) {
+        if (menu instanceof TypeSelectionHolder) {
             event.setCancelled(true);
             if (event.getClickedInventory() != event.getInventory()) return;
             ItemStack clicked = event.getCurrentItem();
@@ -236,7 +238,7 @@ public void onClick(InventoryClickEvent event) {
             }
             return;
         }
-        if (event.getInventory().getHolder() instanceof PartSelectionHolder holder) {
+        if (menu instanceof PartSelectionHolder holder) {
             event.setCancelled(true);
             if (event.getClickedInventory() != event.getInventory()) return;
             ItemStack clicked = event.getCurrentItem();
diff --git a/src/main/java/net/tfminecraft/magic/listener/MagicSessionListener.java b/src/main/java/net/tfminecraft/magic/listener/MagicSessionListener.java
index c7bcf7c..4ba18ff 100644
--- a/src/main/java/net/tfminecraft/magic/listener/MagicSessionListener.java
+++ b/src/main/java/net/tfminecraft/magic/listener/MagicSessionListener.java
@@ -62,7 +62,7 @@ private void clearActivities(Player player, net.tfminecraft.tlibs.character.Char
         clearActivities(player, outgoing, true);
     }
     private void clearActivities(Player player, net.tfminecraft.tlibs.character.CharacterSession outgoing, boolean clearGear) {
-        Object holder = player.getOpenInventory().getTopInventory().getHolder();
+        Object holder = player.getOpenInventory().getTopInventory().getHolder(false);
         MeditationService.cancel(player);
         SacrificeRiteService.cancelForPlayer(player.getUniqueId());
         var captured = outgoing == null ? null : net.tfminecraft.magic.gear.ownership.GearCharacterBridge.token(outgoing);
@@ -88,7 +88,7 @@ private void clearActivities(Player player, net.tfminecraft.tlibs.character.Char
     }
     private void clearStaleGear(Player player) {
         GearOrbService.finishStaleForPlayer(player.getUniqueId()); GearChargeService.clearStale(player);
-        if (player.getOpenInventory().getTopInventory().getHolder() instanceof net.tfminecraft.magic.gear.gui.GearMenuHolder gear && !gear.current(player)) player.closeInventory();
+        if (player.getOpenInventory().getTopInventory().getHolder(false) instanceof net.tfminecraft.magic.gear.gui.GearMenuHolder gear && !gear.current(player)) player.closeInventory();
         if (OpenStationManager.get(player) == null) {
             OpenStationManager.clear(player); SelectedPartsManager.clear(player); TypeSelectionManager.clear(player);
         }
diff --git a/src/main/java/net/tfminecraft/magic/manager/ArtifactCreateGuiManager.java b/src/main/java/net/tfminecraft/magic/manager/ArtifactCreateGuiManager.java
index 7c8eae3..38aa8a3 100644
--- a/src/main/java/net/tfminecraft/magic/manager/ArtifactCreateGuiManager.java
+++ b/src/main/java/net/tfminecraft/magic/manager/ArtifactCreateGuiManager.java
@@ -58,7 +58,7 @@ public void onInventoryClick(InventoryClickEvent event) {
         if (!(event.getWhoClicked() instanceof Player player)) {
             return;
         }
-        if (!(event.getView().getTopInventory().getHolder() instanceof ArtifactCreateGuiHolder holder)) {
+        if (!(event.getView().getTopInventory().getHolder(false) instanceof ArtifactCreateGuiHolder holder)) {
             return;
         }
         event.setCancelled(true);
@@ -152,7 +152,7 @@ private static void giveOrDrop(Player player, ItemStack stack) {
 
     @EventHandler
     public void onInventoryDrag(InventoryDragEvent event) {
-        if (!(event.getView().getTopInventory().getHolder() instanceof ArtifactCreateGuiHolder)) {
+        if (!(event.getView().getTopInventory().getHolder(false) instanceof ArtifactCreateGuiHolder)) {
             return;
         }
         event.setCancelled(true);
@@ -163,7 +163,7 @@ public void onInventoryClose(InventoryCloseEvent event) {
         if (!(event.getPlayer() instanceof Player player)) {
             return;
         }
-        if (!(event.getView().getTopInventory().getHolder() instanceof ArtifactCreateGuiHolder holder)) {
+        if (!(event.getView().getTopInventory().getHolder(false) instanceof ArtifactCreateGuiHolder holder)) {
             return;
         }
         sessions.remove(player.getUniqueId(), holder.getSession());
diff --git a/src/main/java/net/tfminecraft/magic/manager/ResonanceGuiManager.java b/src/main/java/net/tfminecraft/magic/manager/ResonanceGuiManager.java
index f33695a..ccc6279 100644
--- a/src/main/java/net/tfminecraft/magic/manager/ResonanceGuiManager.java
+++ b/src/main/java/net/tfminecraft/magic/manager/ResonanceGuiManager.java
@@ -55,7 +55,7 @@ public void open(Player player) {
     public void refreshOpenInventories() {
         for (Player player : Bukkit.getOnlinePlayers()) {
             Inventory top = player.getOpenInventory().getTopInventory();
-            if (!(top.getHolder() instanceof ResonanceGuiHolder holder)) {
+            if (!(top.getHolder(false) instanceof ResonanceGuiHolder holder)) {
                 continue;
             }
             ResonanceSession session = currentSession(player, holder);
@@ -72,7 +72,7 @@ public void onInventoryClick(InventoryClickEvent event) {
         if (!(event.getWhoClicked() instanceof Player player)) {
             return;
         }
-        if (!(event.getView().getTopInventory().getHolder() instanceof ResonanceGuiHolder holder)) {
+        if (!(event.getView().getTopInventory().getHolder(false) instanceof ResonanceGuiHolder holder)) {
             return;
         }
         event.setCancelled(true);
@@ -128,14 +128,14 @@ private static String castModeChatLabel(String modeId) {
 
     @EventHandler
     public void onInventoryDrag(InventoryDragEvent event) {
-        if (!(event.getView().getTopInventory().getHolder() instanceof ResonanceGuiHolder)) {
+        if (!(event.getView().getTopInventory().getHolder(false) instanceof ResonanceGuiHolder)) {
             return;
         }
         event.setCancelled(true);
     }
 
     public void close(Player player) {
-        if (player.getOpenInventory().getTopInventory().getHolder() instanceof ResonanceGuiHolder) {
+        if (player.getOpenInventory().getTopInventory().getHolder(false) instanceof ResonanceGuiHolder) {
             player.closeInventory();
         }
     }
diff --git a/src/test/java/net/tfminecraft/magic/AttunementTest.java b/src/test/java/net/tfminecraft/magic/AttunementTest.java
index 3f6afb2..c5f28bb 100644
--- a/src/test/java/net/tfminecraft/magic/AttunementTest.java
+++ b/src/test/java/net/tfminecraft/magic/AttunementTest.java
@@ -24,7 +24,7 @@ class AttunementTest {
 
   @BeforeEach
   void setup() {
-    server = MockBukkit.mock();
+    server = MockBukkit.mock(new HolderLookupServerMock());
     server.addSimpleWorld("display");
     Magic.plugin = mock(Magic.class);
     when(Magic.plugin.namespace()).thenReturn("magic");
@@ -207,7 +207,7 @@ void careAcceptsPlayerInventoryAndIndexedDisplaysButNotOrdinaryStorage() {
     var chest = server.createInventory(null, 9);
     assertFalse(ArtifactCarePlaces.accepted(null, item));
     assertFalse(ArtifactCarePlaces.accepted(chest, item));
-    assertTrue(ArtifactCarePlaces.accepted(player.getInventory(), item));
+    assertTrue(ArtifactCarePlaces.accepted(HolderLookupServerMock.withHolderLookup(player.getInventory()), item));
     ArtifactDisplayIndex.add(item);
     assertTrue(ArtifactCarePlaces.accepted(chest, item));
   }
diff --git a/src/test/java/net/tfminecraft/magic/ChargeEdgeCoverageTest.java b/src/test/java/net/tfminecraft/magic/ChargeEdgeCoverageTest.java
index 3aa1041..d76f88f 100644
--- a/src/test/java/net/tfminecraft/magic/ChargeEdgeCoverageTest.java
+++ b/src/test/java/net/tfminecraft/magic/ChargeEdgeCoverageTest.java
@@ -69,7 +69,7 @@ void identifiersRejectEmptyMetadataMalformedIdsAndZeroTiers() {
     assertFalse(Artifact.create().isCharge());
     assertFalse(Charge.fromItem(chargeItem()).isArtifact());
     var inventory = mock(Inventory.class);
-    when(inventory.getHolder())
+    when(inventory.getHolder(false))
         .thenReturn(mock(InventoryHolder.class, withSettings().extraInterfaces(ItemFrame.class)));
     assertTrue(ArtifactCarePlaces.accepted(inventory, s));
     ArtifactDisplayIndex.add(s);
diff --git a/src/test/java/net/tfminecraft/magic/GearCoverageSupport.java b/src/test/java/net/tfminecraft/magic/GearCoverageSupport.java
index 895c08c..1cc6c48 100644
--- a/src/test/java/net/tfminecraft/magic/GearCoverageSupport.java
+++ b/src/test/java/net/tfminecraft/magic/GearCoverageSupport.java
@@ -26,7 +26,7 @@ abstract class GearCoverageSupport {
 
   @BeforeEach
   void setupGear() throws Exception {
-    server = MockBukkit.mock();
+    server = MockBukkit.mock(new HolderLookupServerMock());
     Magic.plugin = mock(Magic.class, RETURNS_DEEP_STUBS);
     when(Magic.plugin.getName()).thenReturn("Magic");
     when(Magic.plugin.namespace()).thenReturn("magic");
diff --git a/src/test/java/net/tfminecraft/magic/HolderLookupServerMock.java b/src/test/java/net/tfminecraft/magic/HolderLookupServerMock.java
new file mode 100644
index 0000000..e23dda7
--- /dev/null
+++ b/src/test/java/net/tfminecraft/magic/HolderLookupServerMock.java
@@ -0,0 +1,61 @@
+package net.tfminecraft.magic;
+
+import static org.mockito.ArgumentMatchers.anyBoolean;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.mockingDetails;
+import static org.mockito.Mockito.spy;
+
+import net.kyori.adventure.text.Component;
+import org.bukkit.event.inventory.InventoryType;
+import org.bukkit.inventory.Inventory;
+import org.bukkit.inventory.InventoryHolder;
+import org.mockbukkit.mockbukkit.ServerMock;
+import org.mockbukkit.mockbukkit.inventory.InventoryMock;
+
+/** MockBukkit leaves Paper's non-copying getHolder(boolean) unimplemented; the plugin uses it on hot paths. */
+public class HolderLookupServerMock extends ServerMock {
+
+  /** A spy of {@code inventory} whose getHolder(boolean) answers like getHolder(). */
+  @SuppressWarnings("unchecked")
+  public static <T extends Inventory> T withHolderLookup(T inventory) {
+    if (mockingDetails(inventory).isMock()) return inventory;
+    T spied = spy(inventory);
+    doAnswer(call -> ((Inventory) call.getMock()).getHolder()).when(spied).getHolder(anyBoolean());
+    return spied;
+  }
+
+  @Override
+  public InventoryMock createInventory(InventoryHolder owner, InventoryType type, String title, int size) {
+    return withHolderLookup(super.createInventory(owner, type, title, size));
+  }
+
+  @Override
+  public InventoryMock createInventory(InventoryHolder owner, InventoryType type) {
+    return withHolderLookup(super.createInventory(owner, type));
+  }
+
+  @Override
+  public InventoryMock createInventory(InventoryHolder owner, InventoryType type, Component title) {
+    return withHolderLookup(super.createInventory(owner, type, title));
+  }
+
+  @Override
+  public InventoryMock createInventory(InventoryHolder owner, InventoryType type, String title) {
+    return withHolderLookup(super.createInventory(owner, type, title));
+  }
+
+  @Override
+  public InventoryMock createInventory(InventoryHolder owner, int size) {
+    return withHolderLookup(super.createInventory(owner, size));
+  }
+
+  @Override
+  public InventoryMock createInventory(InventoryHolder owner, int size, Component title) {
+    return withHolderLookup(super.createInventory(owner, size, title));
+  }
+
+  @Override
+  public InventoryMock createInventory(InventoryHolder owner, int size, String title) {
+    return withHolderLookup(super.createInventory(owner, size, title));
+  }
+}
diff --git a/src/test/java/net/tfminecraft/magic/ListenerTest.java b/src/test/java/net/tfminecraft/magic/ListenerTest.java
index f6639b5..89813c9 100644
--- a/src/test/java/net/tfminecraft/magic/ListenerTest.java
+++ b/src/test/java/net/tfminecraft/magic/ListenerTest.java
@@ -28,7 +28,7 @@ class ListenerTest {
 
   @BeforeEach
   void setup() {
-    server = MockBukkit.mock();
+    server = MockBukkit.mock(new HolderLookupServerMock());
     Magic.plugin = mock(Magic.class, RETURNS_DEEP_STUBS);
     when(Magic.plugin.getServer()).thenReturn(server);
     when(Magic.plugin.isEnabled()).thenReturn(true);