diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/capability/item/CombinedItemHandler.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/capability/item/CombinedItemHandler.kt
index 83c426d0f..cd21d7221 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/capability/item/CombinedItemHandler.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/capability/item/CombinedItemHandler.kt
@@ -4,6 +4,7 @@ import com.google.common.collect.ImmutableList
 import net.minecraft.world.item.ItemStack
 import net.neoforged.neoforge.items.IItemHandler
 import ru.dbotthepony.mc.otm.container.ContainerHandler
+import ru.dbotthepony.mc.otm.container.slotted.SlottedContainer
 import java.util.stream.Stream
 
 class CombinedItemHandler(val handlers: ImmutableList<IItemHandler>) : IItemHandler {
@@ -11,7 +12,7 @@ class CombinedItemHandler(val handlers: ImmutableList<IItemHandler>) : IItemHand
 	constructor(handlers: Collection<IItemHandler>) : this(ImmutableList.copyOf(handlers))
 	constructor(vararg handlers: IItemHandler) : this(ImmutableList.copyOf(handlers))
 
-	private val needsChecking = handlers.any { it !is ContainerHandler }
+	private val needsChecking = handlers.any { it !is ContainerHandler && it !is SlottedContainer }
 	private val lastSizes = IntArray(this.handlers.size)
 	private var totalSize = 0
 	private val mappings = ArrayList<Mapping>()