diff --git a/mockk/jvm/src/main/kotlin/io/mockk/ValueClassSupport.kt b/mockk/jvm/src/main/kotlin/io/mockk/ValueClassSupport.kt
deleted file mode 100644
index 1781141b5..000000000
--- a/mockk/jvm/src/main/kotlin/io/mockk/ValueClassSupport.kt
+++ /dev/null
@@ -1,85 +0,0 @@
-package io.mockk
-
-import kotlin.reflect.KClass
-import kotlin.reflect.KProperty1
-import kotlin.reflect.full.declaredMemberProperties
-import kotlin.reflect.full.primaryConstructor
-import kotlin.reflect.jvm.isAccessible
-
-private val valueClassFieldCache = mutableMapOf<KClass<out Any>, KProperty1<out Any, *>>()
-
-/**
- * Get boxed value of any value class
- *
- * @return boxed value of value class, if this is value class, else just itself
- */
-fun <T : Any> T.boxedValue(): Any? {
-    if (!this::class.isValueClass()) return this
-
-    // get backing field
-    val backingField = this::class.valueField()
-
-    // get boxed value
-    @Suppress("UNCHECKED_CAST")
-    return (backingField as KProperty1<T, *>).get(this)
-}
-
-/**
- * Get class of boxed value of any value class
- *
- * @return class of boxed value, if this is value class, else just class of itself
- */
-fun <T : Any> T.boxedClass(): KClass<*> {
-    return this::class.boxedClass()
-}
-
-/**
- * Get the KClass of boxed value if this is a value class.
- *
- * @return class of boxed value, if this is value class, else just class of itself
- */
-fun KClass<*>.boxedClass(): KClass<*> {
-    if (!this.isValueClass()) return this
-
-    // get backing field
-    val backingField = this.valueField()
-
-    // get boxed value
-    return backingField.returnType.classifier as KClass<*>
-}
-
-
-private fun <T : Any> KClass<T>.valueField(): KProperty1<out T, *> {
-    @Suppress("UNCHECKED_CAST")
-    return valueClassFieldCache.getOrPut(this) {
-        require(isValue) { "$this is not a value class" }
-
-        // value classes always have a primary constructor...
-        val constructor = primaryConstructor!!
-        // ...and exactly one constructor parameter
-        val constructorParameter = constructor.parameters.first()
-        // ...with a backing field
-        val backingField = declaredMemberProperties
-            .first { it.name == constructorParameter.name }
-            .apply { isAccessible = true }
-
-        backingField
-    } as KProperty1<out T, *>
-}
-
-private fun <T : Any> KClass<T>.isValueClass() = try {
-    this.isValue
-} catch (_: Throwable) {
-    false
-}
-
-/**
- * POLYFILL for kotlin version < 1.5
- * will be shadowed by implementation in kotlin SDK 1.5+
- *
- * @return true if this is an inline class, else false
- */
-private val <T : Any> KClass<T>.isValue: Boolean
-    get() = !isData &&
-            primaryConstructor?.parameters?.size == 1 &&
-            java.declaredMethods.any { it.name == "box-impl" }