diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/core/util/WriteOnce.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/core/util/WriteOnce.kt
index bda267313..7f2148bdf 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/core/util/WriteOnce.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/core/util/WriteOnce.kt
@@ -1,17 +1,19 @@
 package ru.dbotthepony.mc.otm.core.util
 
+import ru.dbotthepony.kommons.util.KOptional
 import kotlin.properties.ReadWriteProperty
 import kotlin.reflect.KProperty
 
 class WriteOnce<V>(private val customMessage: String? = null) : ReadWriteProperty<Any?, V> {
-	private var value: V? = null
+	private var value: KOptional<V> = KOptional()
 
 	override fun getValue(thisRef: Any?, property: KProperty<*>): V {
-		return checkNotNull(value) { customMessage ?: "Property ${property.name} is not initialized" }
+		value.ifPresent { return it }
+		throw IllegalStateException(customMessage ?: "Property ${property.name} is not initialized")
 	}
 
 	override fun setValue(thisRef: Any?, property: KProperty<*>, value: V) {
-		check(this.value == null) { "Property ${property.name} is already initialized" }
-		this.value = value
+		this.value.ifPresent { throw IllegalStateException("Property ${property.name} is already initialized") }
+		this.value = KOptional(value)
 	}
 }