diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/container/ItemFilter.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/container/ItemFilter.kt
index cd11e2b6b..dcad21601 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/container/ItemFilter.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/container/ItemFilter.kt
@@ -113,7 +113,7 @@ class ItemFilter private constructor(private val filter: Array<ItemStack>, val i
 		val CODEC: Codec<ItemFilter> by lazy {
 			RecordCodecBuilder.create<ItemFilter> {
 				it.group(
-					Codec.list(ItemStack.CODEC, 0, 40).fieldOf("filter").forGetter { ObjectArrayList.wrap(it.filter) },
+					Codec.list(ItemStack.OPTIONAL_CODEC, 0, 40).fieldOf("filter").forGetter { ObjectArrayList.wrap(it.filter) },
 					Codec.BOOL.optionalFieldOf("isWhitelist", false).forGetter { it.isWhitelist },
 					Codec.BOOL.optionalFieldOf("matchTag", false).forGetter { it.matchTag },
 					Codec.BOOL.optionalFieldOf("matchComponents", false).forGetter { it.matchComponents },
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 4cb739c74..b2a65c25b 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/container/MatteryContainer.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/container/MatteryContainer.kt
@@ -191,7 +191,7 @@ open class MatteryContainer(var listener: ContainerListener, private val size: I
 		companion object {
 			val CODEC: Codec<SerializedItem> = RecordCodecBuilder.create {
 				it.group(
-					ItemStack.CODEC.fieldOf("item").forGetter { it.item },
+					ItemStack.OPTIONAL_CODEC.fieldOf("item").forGetter { it.item },
 					Codec.INT.minRange(0).fieldOf("slot").forGetter { it.slot },
 				).apply(it, ::SerializedItem)
 			}