diff --git a/kotlin-plugin/build.gradle b/kotlin-plugin/build.gradle
index d7216bf..6a2b5f2 100644
--- a/kotlin-plugin/build.gradle
+++ b/kotlin-plugin/build.gradle
@@ -10,8 +10,7 @@ dependencies {
     implementation "org.jetbrains.kotlin:kotlin-gradle-plugin-api"
     compileOnly "org.jetbrains.kotlin:kotlin-compiler-embeddable"
 
-    // testImplementation 'com.github.tschuchortdev:kotlin-compile-testing:1.5.0' does not support Kotlin 2
-    testImplementation 'dev.zacsweers.kctfork:core:0.6.0' // Fork of kotlin-compile-testing that supports Kotlin 2
+    testImplementation 'dev.zacsweers.kctfork:core:0.6.0'
     testImplementation 'junit:junit:4.13.2'
     testImplementation 'org.jetbrains.kotlin:kotlin-compiler-embeddable'
 }
diff --git a/kotlin-plugin/src/main/kotlin/me/shika/ComponentRegistrar.kt b/kotlin-plugin/src/main/kotlin/me/shika/ComponentRegistrar.kt
index bf38a41..931b54c 100644
--- a/kotlin-plugin/src/main/kotlin/me/shika/ComponentRegistrar.kt
+++ b/kotlin-plugin/src/main/kotlin/me/shika/ComponentRegistrar.kt
@@ -2,9 +2,7 @@ package me.shika
 
 import me.shika.ObjectSerializationCommandLineProcessor.Companion.KEY_ENABLED
 import me.shika.generation.ObjectSerializationIrGeneration
-import me.shika.generation.ObjectSerializationJvmGeneration
 import org.jetbrains.kotlin.backend.common.extensions.IrGenerationExtension
-import org.jetbrains.kotlin.codegen.extensions.ExpressionCodegenExtension
 import org.jetbrains.kotlin.compiler.plugin.CompilerPluginRegistrar
 import org.jetbrains.kotlin.compiler.plugin.ExperimentalCompilerApi
 import org.jetbrains.kotlin.config.CompilerConfiguration
@@ -19,10 +17,6 @@ class ObjectSerializationCompilerPluginRegistrar : CompilerPluginRegistrar() {
             return
         }
 
-        ExpressionCodegenExtension.registerExtension(
-            ObjectSerializationJvmGeneration()
-        )
-
         IrGenerationExtension.registerExtension(
             ObjectSerializationIrGeneration()
         )
diff --git a/kotlin-plugin/src/main/kotlin/me/shika/generation/ObjectSerializationJvmGeneration.kt b/kotlin-plugin/src/main/kotlin/me/shika/generation/ObjectSerializationJvmGeneration.kt
deleted file mode 100644
index 3227965..0000000
--- a/kotlin-plugin/src/main/kotlin/me/shika/generation/ObjectSerializationJvmGeneration.kt
+++ /dev/null
@@ -1,43 +0,0 @@
-package me.shika.generation
-
-import org.jetbrains.kotlin.codegen.FunctionCodegen
-import org.jetbrains.kotlin.codegen.ImplementationBodyCodegen
-import org.jetbrains.kotlin.codegen.extensions.ExpressionCodegenExtension
-import org.jetbrains.kotlin.com.intellij.util.ArrayUtil.EMPTY_STRING_ARRAY
-import org.jetbrains.kotlin.resolve.jvm.diagnostics.JvmDeclarationOrigin.Companion.NO_ORIGIN
-import org.jetbrains.org.objectweb.asm.Opcodes.ACC_PUBLIC
-import org.jetbrains.org.objectweb.asm.Opcodes.ACC_SYNTHETIC
-import org.jetbrains.org.objectweb.asm.commons.InstructionAdapter
-
-class ObjectSerializationJvmGeneration : ExpressionCodegenExtension {
-    override fun generateClassSyntheticParts(codegen: ImplementationBodyCodegen) {
-        if (codegen.descriptor.needSerializableFix()) {
-            val selfType = codegen.typeMapper.mapType(codegen.descriptor)
-
-            codegen.addReadResolveFunction {
-                getstatic(codegen.className, "INSTANCE", selfType.descriptor)
-                areturn(selfType)
-            }
-        }
-
-    }
-
-    private fun ImplementationBodyCodegen.addReadResolveFunction(
-        block: InstructionAdapter.() -> Unit
-    ) {
-        val visitor = v.newMethod(
-            NO_ORIGIN,
-            ACC_PUBLIC or ACC_SYNTHETIC,
-            SERIALIZABLE_READ.identifier,
-            "()Ljava/lang/Object;",
-            null,
-            EMPTY_STRING_ARRAY
-        )
-
-        visitor.visitCode()
-        val iv = InstructionAdapter(visitor)
-        iv.apply(block)
-        FunctionCodegen.endVisit(iv, "JVM serialization bindings")
-    }
-
-}
diff --git a/kotlin-plugin/src/main/kotlin/me/shika/generation/utils.kt b/kotlin-plugin/src/main/kotlin/me/shika/generation/utils.kt
index 489c70f..0ac66aa 100644
--- a/kotlin-plugin/src/main/kotlin/me/shika/generation/utils.kt
+++ b/kotlin-plugin/src/main/kotlin/me/shika/generation/utils.kt
@@ -20,20 +20,6 @@ import org.jetbrains.kotlin.resolve.descriptorUtil.getSuperInterfaces
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
 import java.io.Serializable
 
-fun ClassDescriptor.needSerializableFix() =
-    module.platform.has<JvmPlatform>()
-        && DescriptorUtils.isObject(this)
-        && isSerializable()
-        && !hasReadMethod()
-
-fun ClassDescriptor.hasReadMethod() =
-    unsubstitutedMemberScope.getContributedFunctions(SERIALIZABLE_READ, NoLookupLocation.FROM_BACKEND)
-        .any { it.name == SERIALIZABLE_READ && it.valueParameters.isEmpty() }
-
-fun ClassDescriptor.isSerializable(): Boolean =
-    getSuperInterfaces().any { it.fqNameSafe == SERIALIZABLE_FQ_NAME || it.isSerializable() }
-        || getSuperClassNotAny()?.isSerializable() == true
-
 fun IrClass.needSerializableFix(): Boolean {
     return isObject && isSerializable() && !hasReadMethod()
 }
diff --git a/kotlin-plugin/src/test/kotlin/me/shika/ObjectSerializationFixTest.kt b/kotlin-plugin/src/test/kotlin/me/shika/ObjectSerializationFixTest.kt
index dc2b789..c0f408a 100644
--- a/kotlin-plugin/src/test/kotlin/me/shika/ObjectSerializationFixTest.kt
+++ b/kotlin-plugin/src/test/kotlin/me/shika/ObjectSerializationFixTest.kt
@@ -5,13 +5,24 @@ import com.tschuchort.compiletesting.SourceFile
 import org.jetbrains.kotlin.compiler.plugin.ExperimentalCompilerApi
 import org.junit.Assert.assertTrue
 import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.Parameterized
+import org.junit.runners.Parameterized.Parameters
 import java.lang.reflect.Method
 
 @OptIn(ExperimentalCompilerApi::class)
-class ObjectSerializationFixTest {
+@RunWith(Parameterized::class)
+class ObjectSerializationFixTest(enableFir: Boolean) {
+    companion object {
+        @Parameters(name = "FIR: {1}")
+        @JvmStatic
+        fun data() = arrayOf(false, true)
+    }
+
     private val compiler = KotlinCompilation().apply {
         compilerPluginRegistrars = listOf(ObjectSerializationCompilerPluginRegistrar())
         supportsK2 = true
+        languageVersion = if (enableFir) "1.9" else "2.0"
     }
 
     private val SERIALIZABLE_OBJECT = """