diff --git a/libraries/tools/kotlin-main-kts-test/test/org/jetbrains/kotlin/mainKts/test/mainKtsIT.kt b/libraries/tools/kotlin-main-kts-test/test/org/jetbrains/kotlin/mainKts/test/mainKtsIT.kt
index b99228bec70..370a9a1333d 100644
--- a/libraries/tools/kotlin-main-kts-test/test/org/jetbrains/kotlin/mainKts/test/mainKtsIT.kt
+++ b/libraries/tools/kotlin-main-kts-test/test/org/jetbrains/kotlin/mainKts/test/mainKtsIT.kt
@@ -138,8 +138,9 @@ class MainKtsIT {
         }
     }
 
+    @Ignore // see #KT-66395
     @Test
-    fun testHelloSerialization() {
+    fun ignore_testHelloSerialization() {
         val paths = PathUtil.kotlinPathsForDistDirectory
         val serializationPlugin = paths.jar(KotlinPaths.Jar.SerializationPlugin)
         runWithKotlinc(
diff --git a/libraries/tools/kotlin-main-kts-test/test/org/jetbrains/kotlin/mainKts/test/mainKtsTest.kt b/libraries/tools/kotlin-main-kts-test/test/org/jetbrains/kotlin/mainKts/test/mainKtsTest.kt
index b5904545a2b..975fd4a3a2a 100644
--- a/libraries/tools/kotlin-main-kts-test/test/org/jetbrains/kotlin/mainKts/test/mainKtsTest.kt
+++ b/libraries/tools/kotlin-main-kts-test/test/org/jetbrains/kotlin/mainKts/test/mainKtsTest.kt
@@ -245,8 +245,9 @@ class MainKtsTest {
         assertSucceeded(res)
     }
 
+    @Ignore // see #KT-66395
     @Test
-    fun testHelloSerialization() = expectTestToFailOnK2 {
+    fun ignore_testHelloSerialization() {
         // the embeddable plugin is needed for this test, because embeddable compiler is used.
         val serializationPluginClasspath = System.getProperty("kotlin.script.test.kotlinx.serialization.plugin.classpath")!!
         val out = captureOut {