diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/container/MatteryContainer.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/container/MatteryContainer.kt
index 9061de489..688d803cd 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/container/MatteryContainer.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/container/MatteryContainer.kt
@@ -44,8 +44,17 @@ import java.util.stream.StreamSupport
 import kotlin.collections.ArrayList
 
 @Suppress("UNUSED")
-open class MatteryContainer(protected val watcher: Runnable, private val size: Int) : IMatteryContainer, INBTSerializable<Tag?>, StackedContentsCompatible {
-	constructor(size: Int) : this({}, size)
+open class MatteryContainer(var listener: ContainerListener, private val size: Int) : IMatteryContainer, INBTSerializable<Tag?>, StackedContentsCompatible {
+	constructor(watcher: () -> Unit, size: Int) : this({ _, _, _ -> watcher.invoke() }, size)
+	constructor(size: Int) : this(EmptyListener, size)
+
+	fun interface ContainerListener {
+		fun setChanged(slot: Int, new: ItemStack, old: ItemStack)
+	}
+
+	object EmptyListener : ContainerListener {
+		override fun setChanged(slot: Int, new: ItemStack, old: ItemStack) {}
+	}
 
 	init {
 		require(size >= 0) { "Invalid container size $size" }
@@ -254,7 +263,7 @@ open class MatteryContainer(protected val watcher: Runnable, private val size: I
 	}
 
 	protected open fun setChanged(slot: Int, new: ItemStack, old: ItemStack) {
-		watcher.run()
+		listener.setChanged(slot, new, old)
 	}
 
 	override fun serializeNBT(): CompoundTag {
diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/container/MatteryCraftingContainer.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/container/MatteryCraftingContainer.kt
index 3da9b65a8..27f03529e 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/container/MatteryCraftingContainer.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/container/MatteryCraftingContainer.kt
@@ -23,9 +23,18 @@ object DummyMenu : AbstractContainerMenu(null, 0) {
 }
 
 // урод
-open class MatteryCraftingContainer private constructor(watcher: Runnable, width: Int, height: Int, private val parent: MatteryContainer) : CraftingContainer(DummyMenu, width, height), IMatteryContainer by parent, INBTSerializable<CompoundTag?> {
-	constructor(width: Int, height: Int) : this({}, width, height)
-	constructor(watcher: Runnable, width: Int, height: Int) : this(watcher, width, height, MatteryContainer(watcher, width * height))
+open class MatteryCraftingContainer private constructor(private val listener: MatteryContainer.ContainerListener, width: Int, height: Int, private val parent: MatteryContainer) : CraftingContainer(DummyMenu, width, height), IMatteryContainer by parent, INBTSerializable<CompoundTag?> {
+	constructor(width: Int, height: Int) : this(MatteryContainer.EmptyListener, width, height)
+	constructor(listener: () -> Unit, width: Int, height: Int) : this({ _, _, _ -> listener.invoke() }, width, height, MatteryContainer(width * height))
+	constructor(listener: MatteryContainer.ContainerListener, width: Int, height: Int) : this(listener, width, height, MatteryContainer(width * height))
+
+	init {
+		parent.listener = MatteryContainer.ContainerListener { slot, new, old -> this@MatteryCraftingContainer.setChanged(slot, new, old) }
+	}
+
+	protected open fun setChanged(slot: Int, new: ItemStack, old: ItemStack) {
+		listener.setChanged(slot, new, old)
+	}
 
 	override fun serializeNBT(): CompoundTag {
 		return parent.serializeNBT()
diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/container/UpgradeContainer.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/container/UpgradeContainer.kt
index a8fa5095e..35abc5839 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/container/UpgradeContainer.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/container/UpgradeContainer.kt
@@ -10,8 +10,8 @@ import ru.dbotthepony.mc.otm.core.collect.reduce
 import ru.dbotthepony.mc.otm.core.math.Decimal
 import kotlin.math.pow
 
-open class UpgradeContainer(slotCount: Int, open val allowedUpgrades: Set<UpgradeType> = UpgradeType.ALL, watcher: Runnable = Runnable {}) : MatteryContainer(watcher, slotCount), IMatteryUpgrade {
-	constructor(watcher: Runnable, slotCount: Int, allowedUpgrades: Set<UpgradeType>) : this(slotCount, allowedUpgrades, watcher)
+open class UpgradeContainer(slotCount: Int, open val allowedUpgrades: Set<UpgradeType> = UpgradeType.ALL, listener: ContainerListener = EmptyListener) : MatteryContainer(listener, slotCount), IMatteryUpgrade {
+	constructor(listener: () -> Unit, slotCount: Int, allowedUpgrades: Set<UpgradeType>) : this(slotCount, allowedUpgrades, { _, _, _ -> listener.invoke() })
 
 	final override val upgradeTypes: Set<UpgradeType>
 		get() = setOf()