diff --git a/pom.xml b/pom.xml
index f2c68b7..c6baa7e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -64,7 +64,7 @@
         <!-- Do not change unless you want different name for local builds. -->
         <build.number>-LOCAL</build.number>
         <!-- This allows to change between versions. -->
-        <build.version>1.17.0</build.version>
+        <build.version>1.17.1</build.version>
         <!-- Sonar Cloud -->
         <sonar.projectKey>BentoBoxWorld_addon-invSwitcher</sonar.projectKey>
         <sonar.organization>bentobox-world</sonar.organization>
@@ -238,6 +238,7 @@
                 <version>3.13.0</version>
                 <configuration>
                     <release>${java.version}</release>
+                    <forceJavacCompilerUse>true</forceJavacCompilerUse>
                 </configuration>
             </plugin>
             <plugin>
diff --git a/src/main/java/com/wasteofplastic/invswitcher/Store.java b/src/main/java/com/wasteofplastic/invswitcher/Store.java
index 7fc4feb..5ef1022 100644
--- a/src/main/java/com/wasteofplastic/invswitcher/Store.java
+++ b/src/main/java/com/wasteofplastic/invswitcher/Store.java
@@ -31,6 +31,7 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.CompletableFuture;
 import java.util.stream.Collectors;
@@ -64,6 +65,7 @@
 public class Store {
     private static final CharSequence THE_END = "_the_end";
     private static final CharSequence NETHER = "_nether";
+    static final String DEFAULT_WORLD_KEY = "default";
     private final Database<InventoryStorage> database;
     private final Map<UUID, InventoryStorage> cache;
     private final Map<UUID, String> currentKey;
@@ -108,6 +110,9 @@ public String getStorageKey(Player player, World world, Island island) {
      * @return storage key
      */
     String getStorageKey(Player player, World world, Location location, Island island) {
+        if (!addon.getWorlds().contains(world)) {
+            return DEFAULT_WORLD_KEY;
+        }
         String overworldName = getOverworldName(world);
 
         if (!addon.getSettings().isIslandsActive()) {
@@ -159,9 +164,27 @@ String getStorageKey(Player player, World world, Location location, Island islan
      * @return overworld name
      */
     private String getOverworldName(World world) {
+        if (!addon.getWorlds().contains(world)) {
+            return DEFAULT_WORLD_KEY;
+        }
         return (world.getName().replace(THE_END, "")).replace(NETHER, "");
     }
 
+    private String findOldNonBentoBoxKey(InventoryStorage store) {
+        if (store.getInventory() == null) {
+            return null;
+        }
+        Set<String> bentoboxOverworlds = addon.getWorlds().stream()
+            .map(w -> (w.getName().replace(THE_END, "")).replace(NETHER, ""))
+            .collect(Collectors.toSet());
+        return store.getInventory().keySet().stream()
+            .filter(k -> !k.contains("/"))
+            .filter(k -> !bentoboxOverworlds.contains(k))
+            .filter(k -> !DEFAULT_WORLD_KEY.equals(k))
+            .findFirst()
+            .orElse(null);
+    }
+
     /**
      * Get the current storage key for a player.
      * @param player - player
@@ -209,10 +232,20 @@ public void getInventory(Player player, World world, Island island) {
         // Always track the island-level key so future saves and island detection work correctly
         currentKey.put(player.getUniqueId(), islandKey);
 
+        // Migration: non-BentoBox worlds previously stored data under individual world names.
+        // Now they share DEFAULT_WORLD_KEY. Find and migrate old data on first access.
+        String islandLoadKey = islandKey;
+        if (DEFAULT_WORLD_KEY.equals(islandKey) && !store.isInventory(islandKey)) {
+            String oldKey = findOldNonBentoBoxKey(store);
+            if (oldKey != null) {
+                islandLoadKey = oldKey;
+                store.clearWorldData(oldKey);
+            }
+        }
+
         // Backward compat: if island-specific key has no data, migrate from world-only key.
         // This only happens once — the world-only data is cleared after migration so that
         // other islands don't also inherit a duplicate copy.
-        String islandLoadKey = islandKey;
         if (islandKey.contains("/") && !store.isInventory(islandKey)) {
             if (store.isInventory(worldKey)) {
                 islandLoadKey = worldKey;
diff --git a/src/test/java/com/wasteofplastic/invswitcher/StoreTest.java b/src/test/java/com/wasteofplastic/invswitcher/StoreTest.java
index ac4feba..dfe5419 100644
--- a/src/test/java/com/wasteofplastic/invswitcher/StoreTest.java
+++ b/src/test/java/com/wasteofplastic/invswitcher/StoreTest.java
@@ -21,7 +21,9 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Comparator;
+import java.util.HashSet;
 import java.util.Optional;
+import java.util.Set;
 import java.util.UUID;
 import java.util.logging.Logger;
 
@@ -78,6 +80,8 @@ public class StoreTest {
 
     private Settings sets;
 
+    private Set<World> bentoboxWorlds;
+
     private UUID playerUUID;
 
     @Mock
@@ -131,6 +135,11 @@ public void setUp() throws Exception {
         DatabaseType mockDbt = mock(DatabaseType.class);
         when(bbSettings.getDatabaseType()).thenReturn(mockDbt);
 
+        // Register world as a BentoBox world
+        bentoboxWorlds = new HashSet<>();
+        bentoboxWorlds.add(world);
+        when(addon.getWorlds()).thenReturn(bentoboxWorlds);
+
         // Disable island switching by default for existing tests
         sets.setIslandsActive(false);
 
@@ -378,6 +387,7 @@ public void testGetStorageKeyGenericNether() {
         World netherWorld = mock(World.class);
         when(netherWorld.getName()).thenReturn("world_nether");
         when(netherWorld.getEnvironment()).thenReturn(Environment.NETHER);
+        bentoboxWorlds.add(netherWorld);
 
         // Set up overworld for Util.getWorld
         World overworld = mock(World.class);
@@ -512,4 +522,83 @@ public void testFullScenarioSingleToMultipleIslands() {
         }
     }
 
+    // --- Non-BentoBox world tests ---
+
+    @Test
+    public void testGetStorageKeyNonBentoBoxWorld() {
+        World otherWorld = mock(World.class);
+        when(otherWorld.getName()).thenReturn("em_adventurers_guild");
+        // otherWorld is NOT in bentoboxWorlds
+        String key = s.getStorageKey(player, otherWorld);
+        assertEquals(Store.DEFAULT_WORLD_KEY, key);
+    }
+
+    @Test
+    public void testAllNonBentoBoxWorldsShareKey() {
+        World world1 = mock(World.class);
+        when(world1.getName()).thenReturn("world");
+        World world2 = mock(World.class);
+        when(world2.getName()).thenReturn("em_adventurers_guild");
+        World world3 = mock(World.class);
+        when(world3.getName()).thenReturn("em_diamond_arena");
+        // None are in bentoboxWorlds
+        assertEquals(Store.DEFAULT_WORLD_KEY, s.getStorageKey(player, world1));
+        assertEquals(Store.DEFAULT_WORLD_KEY, s.getStorageKey(player, world2));
+        assertEquals(Store.DEFAULT_WORLD_KEY, s.getStorageKey(player, world3));
+    }
+
+    @Test
+    public void testBentoBoxToNonBentoBoxRestoresInventory() {
+        sets.setStatistics(false);
+        sets.setAdvancements(false);
+
+        World nonBBWorld = mock(World.class);
+        when(nonBBWorld.getName()).thenReturn("em_adventurers_guild");
+
+        try (MockedStatic<Bukkit> mockedBukkit = mockStatic(Bukkit.class, Mockito.RETURNS_MOCKS)) {
+            // Step 1: Enter BentoBox world from non-BB world — saves "outside" inventory
+            s.storeInventory(player, nonBBWorld);
+            s.getInventory(player, world);
+            assertEquals("world", s.getCurrentKey(player));
+
+            // Step 2: Leave BentoBox world to a DIFFERENT non-BB world
+            s.storeInventory(player, world);
+            s.getInventory(player, nonBBWorld);
+            // Should load from DEFAULT_WORLD_KEY (where step 1 saved)
+            assertEquals(Store.DEFAULT_WORLD_KEY, s.getCurrentKey(player));
+
+            // Verify inventory was loaded (setContents called)
+            verify(player.getInventory(), atLeastOnce()).setContents(any(ItemStack[].class));
+        }
+    }
+
+    @Test
+    public void testMigrationFromOldWorldKey() {
+        sets.setStatistics(false);
+        sets.setAdvancements(false);
+
+        // Simulate old data: inventory was saved under "overworld" (old behavior)
+        World overworld = mock(World.class);
+        when(overworld.getName()).thenReturn("overworld");
+        // Temporarily add overworld to BentoBox worlds so storeAndSave uses "overworld" key
+        bentoboxWorlds.add(overworld);
+
+        try (MockedStatic<Bukkit> mockedBukkit = mockStatic(Bukkit.class, Mockito.RETURNS_MOCKS)) {
+            s.storeInventory(player, overworld);
+            assertTrue(s.isWorldStored(player, overworld));
+        }
+
+        // Now remove overworld from BentoBox worlds (simulating the fix being applied)
+        bentoboxWorlds.remove(overworld);
+
+        // Loading for a non-BB world should migrate from the old "overworld" key
+        World otherWorld = mock(World.class);
+        when(otherWorld.getName()).thenReturn("em_adventurers_guild");
+        s.getInventory(player, otherWorld);
+        assertEquals(Store.DEFAULT_WORLD_KEY, s.getCurrentKey(player));
+
+        // Verify inventory was loaded (migration found the old "overworld" data)
+        verify(player.getInventory(), atLeastOnce()).setContents(any(ItemStack[].class));
+    }
+
 }