diff --git a/modules/mockk-agent-api/src/commonMain/kotlin/io/mockk/proxy/MockKInstantiatior.kt b/modules/mockk-agent-api/src/commonMain/kotlin/io/mockk/proxy/MockKInstantiatior.kt
index d82fb7022..5bc698cba 100644
--- a/modules/mockk-agent-api/src/commonMain/kotlin/io/mockk/proxy/MockKInstantiatior.kt
+++ b/modules/mockk-agent-api/src/commonMain/kotlin/io/mockk/proxy/MockKInstantiatior.kt
@@ -1,5 +1,5 @@
 package io.mockk.proxy
 
 interface MockKInstantiatior {
-    fun <T> instance(cls: Class<T>): T
+    fun <T : Any> instance(cls: Class<T>): T
 }
diff --git a/modules/mockk-agent/src/jvmMain/kotlin/io/mockk/proxy/jvm/ObjenesisInstantiator.kt b/modules/mockk-agent/src/jvmMain/kotlin/io/mockk/proxy/jvm/ObjenesisInstantiator.kt
index ce809c546..e040750af 100644
--- a/modules/mockk-agent/src/jvmMain/kotlin/io/mockk/proxy/jvm/ObjenesisInstantiator.kt
+++ b/modules/mockk-agent/src/jvmMain/kotlin/io/mockk/proxy/jvm/ObjenesisInstantiator.kt
@@ -20,11 +20,16 @@ class ObjenesisInstantiator(
 
     private val instantiators = Collections.synchronizedMap(WeakHashMap<Class<*>, ObjectInstantiator<*>>())
 
-    override fun <T> instance(cls: Class<T>): T {
-        if (cls == Any::class.java) {
+    override fun <T : Any> instance(cls: Class<T>): T {
+        val kcls = cls.kotlin
+        if (kcls == Any::class) {
             @Suppress("UNCHECKED_CAST")
             return Any() as T
-        } else if (!Modifier.isFinal(cls.modifiers)) {
+        } else if (kcls.isSealed) {
+            kcls.sealedSubclasses.firstNotNullOfOrNull { subCls ->
+                runCatching { instance(subCls.java) }.getOrNull()
+            } ?: error("could not find subclass for sealed class $cls")
+        } else if (kcls.isFinal) {
             try {
                 val instance = instantiateViaProxy(cls)
                 if (instance != null) {
diff --git a/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedClassTest.kt b/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedClassTest.kt
index f48c8b1f4..efa39cab2 100644
--- a/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedClassTest.kt
+++ b/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedClassTest.kt
@@ -2,7 +2,6 @@ package io.mockk.it
 
 import io.mockk.every
 import io.mockk.mockk
-import kotlin.test.Ignore
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
@@ -10,7 +9,6 @@ import kotlin.test.assertEquals
 class SealedClassTest {
 
     @Test
-    @Ignore("Fails on JDK17+ https://github.com/mockk/mockk/issues/832")
     fun serviceReturnsSealedClassImpl() {
         val factory = mockk<Factory> {
             every { create() } returns Leaf(1)
@@ -22,7 +20,6 @@ class SealedClassTest {
     }
 
     @Test
-    @Ignore("Fails on JDK17+ https://github.com/mockk/mockk/issues/832")
     fun serviceAnswersSealedClassImpl() {
         val factory = mockk<Factory> {
             every { create() } answers { Leaf(1) }
diff --git a/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedInterfaceTest.kt b/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedInterfaceTest.kt
index 4abe70221..91f727abf 100644
--- a/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedInterfaceTest.kt
+++ b/modules/mockk/src/commonTest/kotlin/io/mockk/it/SealedInterfaceTest.kt
@@ -3,14 +3,12 @@ package io.mockk.it
 import io.mockk.every
 import io.mockk.mockk
 import kotlin.test.Test
-import kotlin.test.Ignore
 import kotlin.test.assertEquals
 
 
 class SealedInterfaceTest {
 
     @Test
-    @Ignore("Fails on JDK17+ https://github.com/mockk/mockk/issues/832")
     fun serviceReturnsSealedClassImpl() {
         val factory = mockk<Factory> {
             every { create() } returns Leaf(1)
@@ -22,7 +20,6 @@ class SealedInterfaceTest {
     }
 
     @Test
-    @Ignore("Fails on JDK17+ https://github.com/mockk/mockk/issues/832")
     fun serviceAnswersSealedClassImpl() {
         val factory = mockk<Factory> {
             every { create() } answers { Leaf(1) }