--- a/net/minecraft/world/level/block/HopperBlock.java
+++ b/net/minecraft/world/level/block/HopperBlock.java
@@ -187,6 +187,7 @@
 
     @Override
     protected void entityInside(BlockState state, Level world, BlockPos pos, Entity entity) {
+        if (!new io.papermc.paper.event.entity.EntityInsideBlockEvent(entity.getBukkitEntity(), org.bukkit.craftbukkit.block.CraftBlock.at(world, pos)).callEvent()) { return; } // Paper - Add EntityInsideBlockEvent
         BlockEntity blockEntity = world.getBlockEntity(pos);
         if (blockEntity instanceof HopperBlockEntity) {
             HopperBlockEntity.entityInside(world, pos, state, entity, (HopperBlockEntity)blockEntity);
