diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/decorative/GrillBlockEntity.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/decorative/GrillBlockEntity.kt
index b909c6932..529c4aaa6 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/decorative/GrillBlockEntity.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/decorative/GrillBlockEntity.kt
@@ -38,7 +38,6 @@ import ru.dbotthepony.mc.otm.core.math.component2
 import ru.dbotthepony.mc.otm.core.math.component3
 import ru.dbotthepony.mc.otm.core.set
 import ru.dbotthepony.mc.otm.core.util.countingLazy
-import ru.dbotthepony.mc.otm.data.codec.KOptionalCodec
 import ru.dbotthepony.mc.otm.data.codec.minRange
 import ru.dbotthepony.mc.otm.menu.decorative.GrillMenu
 import ru.dbotthepony.mc.otm.registry.game.MBlockEntities
@@ -54,7 +53,7 @@ class GrillBlockEntity(blockPos: BlockPos, blockState: BlockState) : MatteryBloc
 		private fun clearSlot() {
 			inputProgress[slot] = 0
 			outputs[slot] = null
-			outputsRecipeNames[slot] = KOptional.empty()
+			outputsRecipeNames[slot] = null
 			activeSlots.rem(slot)
 		}
 
@@ -79,10 +78,10 @@ class GrillBlockEntity(blockPos: BlockPos, blockState: BlockState) : MatteryBloc
 				if (result == null) {
 					clearSlot()
 				} else {
-					if (outputsRecipeNames[slot].orNull() != result.id)
+					if (outputsRecipeNames[slot] != result.id)
 						inputProgress[slot] = 0
 
-					outputsRecipeNames[slot] = KOptional.of(result.id)
+					outputsRecipeNames[slot] = result.id
 					outputs[slot] = result.value
 					activeSlots.add(slot)
 				}
@@ -101,7 +100,7 @@ class GrillBlockEntity(blockPos: BlockPos, blockState: BlockState) : MatteryBloc
 		return customDisplayName ?: level?.getBlockState(blockPos)?.block?.name ?: TextComponent("null at $blockPos")
 	}
 
-	private val outputsRecipeNames = Array<KOptional<ResourceLocation>>(SLOTS) { KOptional.empty() }
+	private val outputsRecipeNames = arrayOfNulls<ResourceLocation>(SLOTS)
 	private val outputs = arrayOfNulls<SmokingRecipe>(SLOTS)
 	private val activeSlots = IntArrayList()
 	private val inputProgress = IntArray(SLOTS)
@@ -138,12 +137,12 @@ class GrillBlockEntity(blockPos: BlockPos, blockState: BlockState) : MatteryBloc
 		savetables.stateful(::fuelSlot)
 		savetables.stateful(::experience)
 
-		outputsRecipeNames.fill(KOptional())
+		outputsRecipeNames.fill(null)
 
 		// TODO: could have been done as list (and get more space efficient storage), but we use an array, oh well
 		for (i in inputProgress.indices) {
 			savetables.codec(Delegate.Of({ inputProgress[i] }, { inputProgress[i] = it }), progressCodec, "inputProgress${i}")
-			savetables.codec(Delegate.Of({ outputsRecipeNames[i] }, { outputsRecipeNames[i] = it }), recipeNameCodec, "recipeName${i}")
+			savetables.codecNullable(Delegate.Of({ outputsRecipeNames[i] }, { outputsRecipeNames[i] = it }), ResourceLocation.CODEC, "recipeName${i}")
 		}
 
 		// addDroppableContainer(inputSlots)
@@ -216,7 +215,6 @@ class GrillBlockEntity(blockPos: BlockPos, blockState: BlockState) : MatteryBloc
 		const val SLOTS = 6
 
 		private val progressCodec = Codec.INT.minRange(0)
-		private val recipeNameCodec = KOptionalCodec(ResourceLocation.CODEC)
 		val FUEL_SLOT_PROVIDER = ContainerSlot.Simple(maxStackSize = 4, filter = AutomationFilters.CHEMICAL_FUEL)
 	}
 }
diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/core/util/Savetables.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/core/util/Savetables.kt
index 238f42d84..9f2e734b6 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/core/util/Savetables.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/core/util/Savetables.kt
@@ -7,6 +7,7 @@ import net.minecraft.core.HolderLookup.Provider
 import net.minecraft.nbt.ByteTag
 import net.minecraft.nbt.CompoundTag
 import net.minecraft.nbt.DoubleTag
+import net.minecraft.nbt.EndTag
 import net.minecraft.nbt.FloatTag
 import net.minecraft.nbt.IntTag
 import net.minecraft.nbt.LongTag
@@ -297,7 +298,7 @@ class Savetables : INBTSerializable<CompoundTag?> {
 		for (entry in entries) {
 			val value = entry.serializeNBT(registry)
 
-			if (value != null)
+			if (value != null && value !is EndTag)
 				nbt[entry.name] = value
 		}
 	}
diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/data/codec/KOptionalCodec.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/data/codec/KOptionalCodec.kt
deleted file mode 100644
index d83207062..000000000
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/data/codec/KOptionalCodec.kt
+++ /dev/null
@@ -1,21 +0,0 @@
-package ru.dbotthepony.mc.otm.data.codec
-
-import com.mojang.datafixers.util.Pair
-import com.mojang.serialization.Codec
-import com.mojang.serialization.DataResult
-import com.mojang.serialization.DynamicOps
-import ru.dbotthepony.kommons.util.KOptional
-
-class KOptionalCodec<E : Any>(val parent: Codec<E>) : Codec<KOptional<E>> {
-	override fun <T> encode(input: KOptional<E>, ops: DynamicOps<T>, prefix: T): DataResult<T> {
-		return input.map { parent.encode(it, ops, prefix) }.orElse { DataResult.success(ops.empty()) }
-	}
-
-	override fun <T> decode(ops: DynamicOps<T>, input: T): DataResult<Pair<KOptional<E>, T>> {
-		if (input == ops.empty()) {
-			return DataResult.success(Pair(KOptional(), ops.empty()))
-		} else {
-			return parent.decode(ops, input).map { Pair(KOptional(it.first), it.second) }
-		}
-	}
-}