diff --git a/src/main/java/de/ellpeck/naturesaura/blocks/BlockSpawnLamp.java b/src/main/java/de/ellpeck/naturesaura/blocks/BlockSpawnLamp.java
index 2ec46d29..137efce4 100644
--- a/src/main/java/de/ellpeck/naturesaura/blocks/BlockSpawnLamp.java
+++ b/src/main/java/de/ellpeck/naturesaura/blocks/BlockSpawnLamp.java
@@ -54,6 +54,8 @@ public class BlockSpawnLamp extends BlockContainerImpl implements IVisualizable,
             return;
         IWorld world = event.getWorld();
         BlockPos pos = new BlockPos(event.getX(), event.getY(), event.getZ());
+        if (!(world instanceof World))
+            return;
         WorldData data = (WorldData) IWorldData.getWorldData((World) world);
         for (TileEntitySpawnLamp lamp : data.spawnLamps) {
             int range = lamp.getRadius();