diff --git a/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirCompilerFacility.kt b/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirCompilerFacility.kt
index df1a23716e3..e8f6a2864ea 100644
--- a/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirCompilerFacility.kt
+++ b/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirCompilerFacility.kt
@@ -267,7 +267,6 @@ internal class KtFirCompilerFacility(
             fir2IrExtensions,
             fir2IrConfiguration,
             irGeneratorExtensions,
-            signatureComposerForJvmFir2Ir(),
             JvmIrMangler,
             FirJvmKotlinMangler(),
             FirJvmVisibilityConverter,
diff --git a/compiler/cli/cli-js/src/org/jetbrains/kotlin/cli/js/klib/compilerPipeline.kt b/compiler/cli/cli-js/src/org/jetbrains/kotlin/cli/js/klib/compilerPipeline.kt
index 89cbedbd9b3..9398d2e2d9a 100644
--- a/compiler/cli/cli-js/src/org/jetbrains/kotlin/cli/js/klib/compilerPipeline.kt
+++ b/compiler/cli/cli-js/src/org/jetbrains/kotlin/cli/js/klib/compilerPipeline.kt
@@ -33,7 +33,6 @@ import org.jetbrains.kotlin.fir.session.KlibIcData
 import org.jetbrains.kotlin.incremental.components.LookupTracker
 import org.jetbrains.kotlin.incremental.js.IncrementalDataProvider
 import org.jetbrains.kotlin.ir.backend.js.*
-import org.jetbrains.kotlin.ir.backend.js.lower.serialization.ir.JsManglerDesc
 import org.jetbrains.kotlin.ir.backend.js.lower.serialization.ir.JsManglerIr
 import org.jetbrains.kotlin.ir.types.IrTypeSystemContextImpl
 import org.jetbrains.kotlin.ir.util.IrMessageLogger
@@ -243,7 +242,6 @@ fun transformFirToIr(
         fir2IrExtensions,
         Fir2IrConfiguration.forKlibCompilation(moduleStructure.compilerConfiguration, diagnosticsReporter),
         IrGenerationExtension.getInstances(moduleStructure.project),
-        signatureComposer = DescriptorSignatureComposerStub(JsManglerDesc),
         irMangler = JsManglerIr,
         firMangler = FirJsKotlinMangler(),
         visibilityConverter = Fir2IrVisibilityConverter.Default,
diff --git a/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/pipeline/compilerPipeline.kt b/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/pipeline/compilerPipeline.kt
index 4cbe2c32098..348663ca99e 100644
--- a/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/pipeline/compilerPipeline.kt
+++ b/compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/pipeline/compilerPipeline.kt
@@ -203,7 +203,6 @@ fun FirResult.convertToIrAndActualizeForJvm(
         fir2IrExtensions,
         fir2IrConfiguration,
         irGeneratorExtensions,
-        signatureComposerForJvmFir2Ir(),
         JvmIrMangler,
         FirJvmKotlinMangler(),
         FirJvmVisibilityConverter,
diff --git a/compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/pipeline/convertToIr.kt b/compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/pipeline/convertToIr.kt
index c069703b817..d2cb5032ec0 100644
--- a/compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/pipeline/convertToIr.kt
+++ b/compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/pipeline/convertToIr.kt
@@ -19,12 +19,10 @@ import org.jetbrains.kotlin.fir.backend.jvm.Fir2IrJvmSpecialAnnotationSymbolProv
 import org.jetbrains.kotlin.fir.declarations.FirFile
 import org.jetbrains.kotlin.fir.resolve.ScopeSession
 import org.jetbrains.kotlin.ir.IrBuiltIns
-import org.jetbrains.kotlin.ir.backend.jvm.serialization.JvmDescriptorMangler
 import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
 import org.jetbrains.kotlin.ir.declarations.impl.IrFactoryImpl
 import org.jetbrains.kotlin.ir.overrides.buildForAll
 import org.jetbrains.kotlin.ir.types.IrTypeSystemContext
-import org.jetbrains.kotlin.ir.util.IdSignatureComposer
 import org.jetbrains.kotlin.ir.util.KotlinMangler
 import org.jetbrains.kotlin.ir.visitors.acceptVoid
 
@@ -43,16 +41,10 @@ data class Fir2IrActualizedResult(
     val irActualizedResult: IrActualizedResult?,
 )
 
-fun signatureComposerForJvmFir2Ir(): IdSignatureComposer {
-    val mangler = JvmDescriptorMangler(null)
-    return DescriptorSignatureComposerStub(mangler)
-}
-
 fun FirResult.convertToIrAndActualize(
     fir2IrExtensions: Fir2IrExtensions,
     fir2IrConfiguration: Fir2IrConfiguration,
     irGeneratorExtensions: Collection<IrGenerationExtension>,
-    signatureComposer: IdSignatureComposer,
     irMangler: KotlinMangler.IrMangler,
     firMangler: FirMangler,
     visibilityConverter: Fir2IrVisibilityConverter,
@@ -60,7 +52,7 @@ fun FirResult.convertToIrAndActualize(
     actualizerTypeContextProvider: (IrBuiltIns) -> IrTypeSystemContext,
     fir2IrResultPostCompute: (ModuleCompilerAnalyzedOutput, Fir2IrResult) -> Unit = { _, _ -> },
 ): Fir2IrActualizedResult {
-    val commonMemberStorage = Fir2IrCommonMemberStorage(signatureComposer, firMangler)
+    val commonMemberStorage = Fir2IrCommonMemberStorage(firMangler)
 
     require(outputs.isNotEmpty()) { "No modules found" }
 
diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/DescriptorSignatureComposerStub.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/DescriptorSignatureComposerStub.kt
deleted file mode 100644
index 3623fa1bbee..00000000000
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/DescriptorSignatureComposerStub.kt
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
- * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
- */
-
-package org.jetbrains.kotlin.fir.backend
-
-import org.jetbrains.kotlin.descriptors.ClassDescriptor
-import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
-import org.jetbrains.kotlin.descriptors.PropertyDescriptor
-import org.jetbrains.kotlin.ir.util.IdSignature
-import org.jetbrains.kotlin.ir.util.IdSignatureComposer
-import org.jetbrains.kotlin.ir.util.KotlinMangler
-
-/**
- * A dummy signature composer that returns `null` for all declaration descriptors.
- */
-class DescriptorSignatureComposerStub(override val mangler: KotlinMangler.DescriptorMangler) : IdSignatureComposer {
-    override fun composeSignature(descriptor: DeclarationDescriptor): IdSignature? {
-        return null
-    }
-
-    override fun composeEnumEntrySignature(descriptor: ClassDescriptor): IdSignature? {
-        return null
-    }
-
-    override fun composeFieldSignature(descriptor: PropertyDescriptor): IdSignature? {
-        return null
-    }
-
-    override fun composeAnonInitSignature(descriptor: ClassDescriptor): IdSignature? {
-        return null
-    }
-
-    override fun withFileSignature(fileSignature: IdSignature.FileSignature, body: () -> Unit) {
-        body()
-    }
-}
diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrCommonMemberStorage.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrCommonMemberStorage.kt
index cfd6758a70c..999a71e8ea6 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrCommonMemberStorage.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrCommonMemberStorage.kt
@@ -11,7 +11,6 @@ import org.jetbrains.kotlin.fir.signaturer.FirBasedSignatureComposer
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.impl.IrFactoryImpl
 import org.jetbrains.kotlin.ir.symbols.*
-import org.jetbrains.kotlin.ir.util.IdSignatureComposer
 import org.jetbrains.kotlin.ir.util.SymbolTable
 import java.util.concurrent.ConcurrentHashMap
 
@@ -22,13 +21,10 @@ import java.util.concurrent.ConcurrentHashMap
  *
  * See `/docs/fir/k2_kmp.md`
  */
-class Fir2IrCommonMemberStorage(
-    signatureComposer: IdSignatureComposer,
-    firMangler: FirMangler
-) {
+class Fir2IrCommonMemberStorage(firMangler: FirMangler) {
     val firSignatureComposer = FirBasedSignatureComposer(firMangler)
 
-    val symbolTable = SymbolTable(signaturer = signatureComposer, irFactory = IrFactoryImpl)
+    val symbolTable = SymbolTable(signaturer = null, irFactory = IrFactoryImpl)
 
     val classCache: MutableMap<FirRegularClass, IrClass> = mutableMapOf()
 
diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrComponents.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrComponents.kt
index fd081afcdef..d00237bbebf 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrComponents.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrComponents.kt
@@ -62,7 +62,6 @@ interface Fir2IrComponents {
     val annotationsFromPluginRegistrar: Fir2IrIrGeneratedDeclarationsRegistrar
 
     interface Manglers {
-        val descriptorMangler: KotlinMangler.DescriptorMangler
         val irMangler: KotlinMangler.IrMangler
         val firMangler: FirMangler
     }
diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrComponentsStorage.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrComponentsStorage.kt
index 6ba7a1e6005..c3e3f5bdade 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrComponentsStorage.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrComponentsStorage.kt
@@ -75,9 +75,6 @@ class Fir2IrComponentsStorage(
         get() = symbolTable.lock
 
     override val manglers: Fir2IrComponents.Manglers = object : Fir2IrComponents.Manglers {
-        override val descriptorMangler: KotlinMangler.DescriptorMangler
-            get() = symbolTable.signaturer.mangler
-
         override val irMangler: KotlinMangler.IrMangler
             get() = irMangler
 
diff --git a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/fragments/FragmentDeclarationGenerator.kt b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/fragments/FragmentDeclarationGenerator.kt
index 121c7aee1b1..8f1f184bb5a 100644
--- a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/fragments/FragmentDeclarationGenerator.kt
+++ b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/fragments/FragmentDeclarationGenerator.kt
@@ -68,7 +68,7 @@ open class FragmentDeclarationGenerator(
             isInline = false,
             isExpect = false,
             returnType = irClass.defaultType,
-            symbol = IrConstructorPublicSymbolImpl(context.symbolTable.signaturer.composeSignature(irClass.descriptor)!!),
+            symbol = IrConstructorPublicSymbolImpl(context.symbolTable.signaturer!!.composeSignature(irClass.descriptor)!!),
             isPrimary = true,
             isExternal = false
         )
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DescriptorSymbolTableExtension.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DescriptorSymbolTableExtension.kt
index 8076ebd362e..800aa66cc9d 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DescriptorSymbolTableExtension.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DescriptorSymbolTableExtension.kt
@@ -38,7 +38,7 @@ open class DescriptorSymbolTableExtension(table: SymbolTable) : SymbolTableExten
         get() = table.nameProvider
 
     private val signatureComposer: IdSignatureComposer
-        get() = table.signaturer
+        get() = table.signaturer!!
 
     private val externalPackageFragmentSlice: SymbolTableSlice<PackageFragmentDescriptor, IrExternalPackageFragment, IrExternalPackageFragmentSymbol> = SymbolTableSlice.Flat(lock)
 
diff --git a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/SymbolTable.kt b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/SymbolTable.kt
index 16fd8836716..0fbe2dcbac4 100644
--- a/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/SymbolTable.kt
+++ b/compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/SymbolTable.kt
@@ -17,7 +17,7 @@ private fun <SymbolOwner : IrSymbolOwner, Symbol : IrBindableSymbol<*, SymbolOwn
 
 @OptIn(SymbolTableInternals::class)
 open class SymbolTable(
-    val signaturer: IdSignatureComposer,
+    val signaturer: IdSignatureComposer?, // TODO: This is `null` only in FIR2IR. Make non-nullable again after KT-64990 is fixed.
     val irFactory: IrFactory,
     val nameProvider: NameProvider = NameProvider.DEFAULT,
 ) : ReferenceSymbolTable {
diff --git a/compiler/ir/serialization.jvm/src/org/jetbrains/kotlin/backend/jvm/serialization/deserializeLazyDeclarations.kt b/compiler/ir/serialization.jvm/src/org/jetbrains/kotlin/backend/jvm/serialization/deserializeLazyDeclarations.kt
index 224a6fc71f0..80ba7b1992b 100644
--- a/compiler/ir/serialization.jvm/src/org/jetbrains/kotlin/backend/jvm/serialization/deserializeLazyDeclarations.kt
+++ b/compiler/ir/serialization.jvm/src/org/jetbrains/kotlin/backend/jvm/serialization/deserializeLazyDeclarations.kt
@@ -94,8 +94,13 @@ fun deserializeFromByteArray(
         deserializer.deserializeDeclaration(declarationProto, setParent = false)
     }
 
-    symbolTable.signaturer.withFileSignature(dummyFileSignature) {
+    val signaturer = symbolTable.signaturer
+    if (signaturer == null) {
         ExternalDependenciesGenerator(symbolTable, irProviders).generateUnboundSymbolsAsDependencies()
+    } else {
+        signaturer.withFileSignature(dummyFileSignature) {
+            ExternalDependenciesGenerator(symbolTable, irProviders).generateUnboundSymbolsAsDependencies()
+        }
     }
     toplevelParent.acceptChildrenVoid(PatchDeclarationParentsVisitor(toplevelParent))
     buildFakeOverridesForLocalClasses(symbolTable, typeSystemContext, symbolDeserializer, toplevelParent)
diff --git a/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/backend/handlers/IrMangledNameAndSignatureDumpHandler.kt b/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/backend/handlers/IrMangledNameAndSignatureDumpHandler.kt
index ac3505ab569..914b2256b95 100644
--- a/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/backend/handlers/IrMangledNameAndSignatureDumpHandler.kt
+++ b/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/backend/handlers/IrMangledNameAndSignatureDumpHandler.kt
@@ -176,7 +176,7 @@ class IrMangledNameAndSignatureDumpHandler(
     private inner class DumpStrategy(
         val module: TestModule,
         val irMangler: KotlinMangler.IrMangler,
-        val descriptorMangler: KotlinMangler.DescriptorMangler,
+        val descriptorMangler: KotlinMangler.DescriptorMangler?,
         val firMangler: FirMangler?,
         val irBuiltIns: IrBuiltIns,
     ) : CustomKotlinLikeDumpStrategy {
@@ -242,7 +242,7 @@ class IrMangledNameAndSignatureDumpHandler(
                     // for computing signature mangled names.
                     firMangler?.addSignatureMangledNameTo(signatureMangledNames, firDeclaration, ComputedBy.FE)
                 } else
-                    descriptorMangler.addSignatureMangledNameTo(signatureMangledNames, symbol.descriptor, ComputedBy.FE)
+                    descriptorMangler?.addSignatureMangledNameTo(signatureMangledNames, symbol.descriptor, ComputedBy.FE)
             }
 
             fun printActualMangledNamesAndSignatures() {
diff --git a/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/backend/ir/IrBackendInput.kt b/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/backend/ir/IrBackendInput.kt
index 0ca974a6999..75ab3b025d2 100644
--- a/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/backend/ir/IrBackendInput.kt
+++ b/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/backend/ir/IrBackendInput.kt
@@ -33,14 +33,15 @@ sealed class IrBackendInput : ResultingArtifact.BackendInput<IrBackendInput>() {
     abstract val irPluginContext: IrPluginContext
 
     /**
-     * The mangler instance that was used to build declaration signatures from (possibly deserialized) K1 descriptors for this backend.
+     * The mangler instance that was used to build declaration signatures from (possibly deserialized) K1 descriptors for this backend,
+     * or `null` if this artifact was compiled using the K2 frontend.
      *
      * This instance can be used to verify signatures in tests.
      *
      * @see org.jetbrains.kotlin.backend.common.serialization.mangle.descriptor.DescriptorMangleComputer
      * @see org.jetbrains.kotlin.ir.util.IdSignature
      */
-    abstract val descriptorMangler: KotlinMangler.DescriptorMangler
+    abstract val descriptorMangler: KotlinMangler.DescriptorMangler?
 
     /**
      * The mangler instance that was used to build declaration signatures from IR declarations for this backend.
@@ -70,7 +71,7 @@ sealed class IrBackendInput : ResultingArtifact.BackendInput<IrBackendInput>() {
         val icData: List<KotlinFileSerializedData>,
         override val diagnosticReporter: BaseDiagnosticsCollector,
         val hasErrors: Boolean,
-        override val descriptorMangler: KotlinMangler.DescriptorMangler,
+        override val descriptorMangler: KotlinMangler.DescriptorMangler?,
         override val irMangler: KotlinMangler.IrMangler,
         override val firMangler: FirMangler?,
         val serializeSingleFile: (KtSourceFile) -> ProtoBuf.PackageFragment,
@@ -80,7 +81,7 @@ sealed class IrBackendInput : ResultingArtifact.BackendInput<IrBackendInput>() {
         override val irModuleFragment: IrModuleFragment,
         override val irPluginContext: IrPluginContext,
         override val diagnosticReporter: BaseDiagnosticsCollector,
-        override val descriptorMangler: KotlinMangler.DescriptorMangler,
+        override val descriptorMangler: KotlinMangler.DescriptorMangler?,
         override val irMangler: KotlinMangler.IrMangler,
         override val firMangler: FirMangler?,
     ) : IrBackendInput() {
@@ -96,7 +97,7 @@ sealed class IrBackendInput : ResultingArtifact.BackendInput<IrBackendInput>() {
         val icData: List<KotlinFileSerializedData>,
         override val diagnosticReporter: BaseDiagnosticsCollector,
         val hasErrors: Boolean,
-        override val descriptorMangler: KotlinMangler.DescriptorMangler,
+        override val descriptorMangler: KotlinMangler.DescriptorMangler?,
         override val irMangler: KotlinMangler.IrMangler,
         override val firMangler: FirMangler?,
         val serializeSingleFile: (KtSourceFile) -> ProtoBuf.PackageFragment,
@@ -107,7 +108,7 @@ sealed class IrBackendInput : ResultingArtifact.BackendInput<IrBackendInput>() {
         val codegenFactory: JvmIrCodegenFactory,
         val backendInput: JvmIrCodegenFactory.JvmIrBackendInput,
         val sourceFiles: List<KtSourceFile>,
-        override val descriptorMangler: KotlinMangler.DescriptorMangler,
+        override val descriptorMangler: KotlinMangler.DescriptorMangler?,
         override val irMangler: KotlinMangler.IrMangler,
         override val firMangler: FirMangler?,
     ) : IrBackendInput() {
@@ -128,7 +129,7 @@ sealed class IrBackendInput : ResultingArtifact.BackendInput<IrBackendInput>() {
         override val irModuleFragment: IrModuleFragment,
         override val irPluginContext: IrPluginContext,
         override val diagnosticReporter: BaseDiagnosticsCollector,
-        override val descriptorMangler: KotlinMangler.DescriptorMangler,
+        override val descriptorMangler: KotlinMangler.DescriptorMangler?,
         override val irMangler: KotlinMangler.IrMangler,
         override val firMangler: FirMangler?,
     ) : IrBackendInput()
diff --git a/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/classic/ClassicFrontend2IrConverter.kt b/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/classic/ClassicFrontend2IrConverter.kt
index f72decfdc3a..130aaceb290 100644
--- a/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/classic/ClassicFrontend2IrConverter.kt
+++ b/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/classic/ClassicFrontend2IrConverter.kt
@@ -75,7 +75,7 @@ class ClassicFrontend2IrConverter(
             codegenFactory,
             conversionResult,
             sourceFiles = emptyList(),
-            descriptorMangler = conversionResult.symbolTable.signaturer.mangler,
+            descriptorMangler = conversionResult.symbolTable.signaturer!!.mangler,
             irMangler = JvmIrMangler,
             firMangler = null,
         )
@@ -114,7 +114,7 @@ class ClassicFrontend2IrConverter(
             icData,
             diagnosticReporter = DiagnosticReporterFactory.createReporter(),
             hasErrors,
-            descriptorMangler = (pluginContext.symbolTable as SymbolTable).signaturer.mangler,
+            descriptorMangler = (pluginContext.symbolTable as SymbolTable).signaturer!!.mangler,
             irMangler = JsManglerIr,
             firMangler = null,
         ) { file ->
@@ -156,7 +156,7 @@ class ClassicFrontend2IrConverter(
             icData,
             diagnosticReporter = DiagnosticReporterFactory.createReporter(),
             hasErrors,
-            descriptorMangler = (pluginContext.symbolTable as SymbolTable).signaturer.mangler,
+            descriptorMangler = (pluginContext.symbolTable as SymbolTable).signaturer!!.mangler,
             irMangler = JsManglerIr,
             firMangler = null,
         ) { file ->
diff --git a/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/fir/AbstractFir2IrNonJvmResultsConverter.kt b/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/fir/AbstractFir2IrNonJvmResultsConverter.kt
index d1a6f6ac286..8219449077d 100644
--- a/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/fir/AbstractFir2IrNonJvmResultsConverter.kt
+++ b/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/fir/AbstractFir2IrNonJvmResultsConverter.kt
@@ -7,14 +7,11 @@ package org.jetbrains.kotlin.test.frontend.fir
 
 import org.jetbrains.kotlin.KtSourceFile
 import org.jetbrains.kotlin.backend.common.extensions.IrGenerationExtension
-import org.jetbrains.kotlin.backend.common.serialization.signature.IdSignatureDescriptor
 import org.jetbrains.kotlin.builtins.DefaultBuiltIns
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
-import org.jetbrains.kotlin.config.CommonConfigurationKeys
 import org.jetbrains.kotlin.config.CompilerConfiguration
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.config.languageVersionSettings
-import org.jetbrains.kotlin.constant.EvaluatedConstTracker
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
 import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
 import org.jetbrains.kotlin.diagnostics.DiagnosticReporterFactory
@@ -35,7 +32,6 @@ import org.jetbrains.kotlin.library.unresolvedDependencies
 import org.jetbrains.kotlin.storage.LockBasedStorageManager
 import org.jetbrains.kotlin.test.backend.ir.IrBackendInput
 import org.jetbrains.kotlin.test.directives.CodegenTestDirectives
-import org.jetbrains.kotlin.test.directives.LanguageSettingsDirectives
 import org.jetbrains.kotlin.test.model.BackendKinds
 import org.jetbrains.kotlin.test.model.Frontend2BackendConverter
 import org.jetbrains.kotlin.test.model.FrontendKinds
@@ -51,7 +47,6 @@ abstract class AbstractFir2IrNonJvmResultsConverter(
     FrontendKinds.FIR,
     BackendKinds.IrBackend
 ) {
-    protected abstract fun createDescriptorMangler(): KotlinMangler.DescriptorMangler
     protected abstract fun createIrMangler(): KotlinMangler.IrMangler
     protected abstract fun createFirMangler(): FirMangler
     protected abstract fun resolveLibraries(module: TestModule, compilerConfiguration: CompilerConfiguration): List<KotlinResolvedLibrary>
@@ -90,7 +85,6 @@ abstract class AbstractFir2IrNonJvmResultsConverter(
             Fir2IrExtensions.Default,
             fir2IrConfiguration,
             module.irGenerationExtensions(testServices),
-            IdSignatureDescriptor(createDescriptorMangler()),
             irMangler,
             createFirMangler(),
             Fir2IrVisibilityConverter.Default,
diff --git a/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/fir/Fir2IrJsWasmResultsConverter.kt b/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/fir/Fir2IrJsWasmResultsConverter.kt
index 4cc76b40af9..2ff4365b2cf 100644
--- a/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/fir/Fir2IrJsWasmResultsConverter.kt
+++ b/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/fir/Fir2IrJsWasmResultsConverter.kt
@@ -23,7 +23,6 @@ import org.jetbrains.kotlin.ir.backend.js.JsFactories
 import org.jetbrains.kotlin.ir.backend.js.KotlinFileSerializedData
 import org.jetbrains.kotlin.ir.backend.js.getSerializedData
 import org.jetbrains.kotlin.ir.backend.js.incrementalDataProvider
-import org.jetbrains.kotlin.ir.backend.js.lower.serialization.ir.JsManglerDesc
 import org.jetbrains.kotlin.ir.backend.js.lower.serialization.ir.JsManglerIr
 import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
 import org.jetbrains.kotlin.ir.util.KotlinMangler
@@ -43,16 +42,12 @@ abstract class Fir2IrJsWasmResultsConverter(testServices: TestServices) : Abstra
         List<KotlinFileSerializedData>,
         BaseDiagnosticsCollector,
         Boolean,
-        KotlinMangler.DescriptorMangler,
+        KotlinMangler.DescriptorMangler?,
         KotlinMangler.IrMangler,
         FirMangler?,
         (KtSourceFile) -> ProtoBuf.PackageFragment
     ) -> IrBackendInput
 
-    override fun createDescriptorMangler(): KotlinMangler.DescriptorMangler {
-        return JsManglerDesc
-    }
-
     override fun createIrMangler(): KotlinMangler.IrMangler {
         return JsManglerIr
     }
@@ -83,7 +78,7 @@ abstract class Fir2IrJsWasmResultsConverter(testServices: TestServices) : Abstra
             compilerConfiguration.incrementalDataProvider?.getSerializedData(sourceFiles) ?: emptyList(),
             diagnosticReporter,
             inputArtifact.hasErrors,
-            manglers.descriptorMangler,
+            /*descriptorMangler = */null,
             manglers.irMangler,
             manglers.firMangler,
         ) { file ->
@@ -108,7 +103,7 @@ abstract class Fir2IrJsWasmResultsConverter(testServices: TestServices) : Abstra
 }
 
 class Fir2IrJsResultsConverter(testServices: TestServices) : Fir2IrJsWasmResultsConverter(testServices) {
-    override val artifactFactory: (IrModuleFragment, IrPluginContext, List<KtSourceFile>, List<KotlinFileSerializedData>, BaseDiagnosticsCollector, Boolean, KotlinMangler.DescriptorMangler, KotlinMangler.IrMangler, FirMangler?, (KtSourceFile) -> ProtoBuf.PackageFragment) -> IrBackendInput
+    override val artifactFactory: (IrModuleFragment, IrPluginContext, List<KtSourceFile>, List<KotlinFileSerializedData>, BaseDiagnosticsCollector, Boolean, KotlinMangler.DescriptorMangler?, KotlinMangler.IrMangler, FirMangler?, (KtSourceFile) -> ProtoBuf.PackageFragment) -> IrBackendInput
         get() = IrBackendInput::JsIrBackendInput
 
     override fun resolveLibraries(module: TestModule, compilerConfiguration: CompilerConfiguration): List<KotlinResolvedLibrary> {
@@ -118,7 +113,7 @@ class Fir2IrJsResultsConverter(testServices: TestServices) : Fir2IrJsWasmResults
 
 
 class Fir2IrWasmResultsConverter(testServices: TestServices) : Fir2IrJsWasmResultsConverter(testServices) {
-    override val artifactFactory: (IrModuleFragment, IrPluginContext, List<KtSourceFile>, List<KotlinFileSerializedData>, BaseDiagnosticsCollector, Boolean, KotlinMangler.DescriptorMangler, KotlinMangler.IrMangler, FirMangler?, (KtSourceFile) -> ProtoBuf.PackageFragment) -> IrBackendInput
+    override val artifactFactory: (IrModuleFragment, IrPluginContext, List<KtSourceFile>, List<KotlinFileSerializedData>, BaseDiagnosticsCollector, Boolean, KotlinMangler.DescriptorMangler?, KotlinMangler.IrMangler, FirMangler?, (KtSourceFile) -> ProtoBuf.PackageFragment) -> IrBackendInput
         get() = IrBackendInput::WasmBackendInput
 
     override fun resolveLibraries(module: TestModule, compilerConfiguration: CompilerConfiguration): List<KotlinResolvedLibrary> {
diff --git a/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/fir/Fir2IrJvmResultsConverter.kt b/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/fir/Fir2IrJvmResultsConverter.kt
index e4e9818e1be..d5282945a20 100644
--- a/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/fir/Fir2IrJvmResultsConverter.kt
+++ b/compiler/tests-common-new/tests/org/jetbrains/kotlin/test/frontend/fir/Fir2IrJvmResultsConverter.kt
@@ -14,11 +14,9 @@ import org.jetbrains.kotlin.cli.jvm.compiler.NoScopeRecordCliBindingTrace
 import org.jetbrains.kotlin.codegen.ClassBuilderFactories
 import org.jetbrains.kotlin.codegen.state.GenerationState
 import org.jetbrains.kotlin.diagnostics.DiagnosticReporterFactory
-import org.jetbrains.kotlin.fir.backend.Fir2IrCommonMemberStorage
 import org.jetbrains.kotlin.fir.backend.Fir2IrConfiguration
 import org.jetbrains.kotlin.fir.backend.jvm.*
 import org.jetbrains.kotlin.fir.pipeline.convertToIrAndActualize
-import org.jetbrains.kotlin.fir.pipeline.signatureComposerForJvmFir2Ir
 import org.jetbrains.kotlin.ir.backend.jvm.serialization.JvmIrMangler
 import org.jetbrains.kotlin.test.backend.ir.IrBackendInput
 import org.jetbrains.kotlin.test.directives.CodegenTestDirectives
@@ -68,7 +66,6 @@ class Fir2IrJvmResultsConverter(
 
         val phaseConfig = configuration.get(CLIConfigurationKeys.PHASE_CONFIG)
 
-        val commonMemberStorage = Fir2IrCommonMemberStorage(signatureComposerForJvmFir2Ir(), FirJvmKotlinMangler())
         val diagnosticReporter = DiagnosticReporterFactory.createReporter()
 
         val compilerConfiguration = compilerConfigurationProvider.getCompilerConfiguration(module)
@@ -78,7 +75,6 @@ class Fir2IrJvmResultsConverter(
             fir2IrExtensions,
             fir2IrConfiguration,
             module.irGenerationExtensions(testServices),
-            signatureComposerForJvmFir2Ir(),
             irMangler,
             FirJvmKotlinMangler(),
             FirJvmVisibilityConverter,
@@ -114,9 +110,9 @@ class Fir2IrJvmResultsConverter(
             codegenFactory,
             backendInput,
             sourceFiles,
-            descriptorMangler = commonMemberStorage.symbolTable.signaturer.mangler,
-            irMangler = irMangler,
-            firMangler = commonMemberStorage.firSignatureComposer.mangler,
+            descriptorMangler = null,
+            irMangler = fir2irResult.components.manglers.irMangler,
+            firMangler = fir2irResult.components.manglers.firMangler,
         )
     }
 }
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Fir2Ir.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Fir2Ir.kt
index 8ea6ea922b9..0be9975cd17 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Fir2Ir.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Fir2Ir.kt
@@ -15,9 +15,7 @@ import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.builtins.konan.KonanBuiltIns
 import org.jetbrains.kotlin.cli.common.CLIConfigurationKeys
 import org.jetbrains.kotlin.cli.common.fir.FirDiagnosticsCompilerResultsReporter
-import org.jetbrains.kotlin.config.CommonConfigurationKeys
 import org.jetbrains.kotlin.config.languageVersionSettings
-import org.jetbrains.kotlin.constant.EvaluatedConstTracker
 import org.jetbrains.kotlin.descriptors.isEmpty
 import org.jetbrains.kotlin.descriptors.konan.isNativeStdlib
 import org.jetbrains.kotlin.diagnostics.DiagnosticReporterFactory
@@ -98,7 +96,6 @@ internal fun PhaseContext.fir2Ir(
             NativeFir2IrExtensions,
             fir2IrConfiguration,
             IrGenerationExtension.getInstances(config.project),
-            signatureComposer = DescriptorSignatureComposerStub(KonanManglerDesc),
             irMangler = KonanManglerIr,
             firMangler = FirNativeKotlinMangler,
             visibilityConverter = Fir2IrVisibilityConverter.Default,
diff --git a/native/native.tests/tests/org/jetbrains/kotlin/konan/test/ClassicFrontend2NativeIrConverter.kt b/native/native.tests/tests/org/jetbrains/kotlin/konan/test/ClassicFrontend2NativeIrConverter.kt
index 4b118695860..4968496e396 100644
--- a/native/native.tests/tests/org/jetbrains/kotlin/konan/test/ClassicFrontend2NativeIrConverter.kt
+++ b/native/native.tests/tests/org/jetbrains/kotlin/konan/test/ClassicFrontend2NativeIrConverter.kt
@@ -133,7 +133,7 @@ class ClassicFrontend2NativeIrConverter(
             moduleFragment,
             pluginContext,
             diagnosticReporter = DiagnosticReporterFactory.createReporter(),
-            descriptorMangler = (pluginContext.symbolTable as SymbolTable).signaturer.mangler,
+            descriptorMangler = (pluginContext.symbolTable as SymbolTable).signaturer!!.mangler,
             irMangler = KonanManglerIr,
             firMangler = null,
         )
diff --git a/native/native.tests/tests/org/jetbrains/kotlin/konan/test/Fir2IrNativeResultsConverter.kt b/native/native.tests/tests/org/jetbrains/kotlin/konan/test/Fir2IrNativeResultsConverter.kt
index be8c4857998..7154d1589d6 100644
--- a/native/native.tests/tests/org/jetbrains/kotlin/konan/test/Fir2IrNativeResultsConverter.kt
+++ b/native/native.tests/tests/org/jetbrains/kotlin/konan/test/Fir2IrNativeResultsConverter.kt
@@ -7,7 +7,6 @@ package org.jetbrains.kotlin.konan.test
 
 import org.jetbrains.kotlin.KtSourceFile
 import org.jetbrains.kotlin.backend.common.serialization.metadata.DynamicTypeDeserializer
-import org.jetbrains.kotlin.backend.konan.serialization.KonanManglerDesc
 import org.jetbrains.kotlin.backend.konan.serialization.KonanManglerIr
 import org.jetbrains.kotlin.builtins.konan.KonanBuiltIns
 import org.jetbrains.kotlin.config.CompilerConfiguration
@@ -30,10 +29,6 @@ import org.jetbrains.kotlin.test.services.TestServices
 
 class Fir2IrNativeResultsConverter(testServices: TestServices) : AbstractFir2IrNonJvmResultsConverter(testServices) {
 
-    override fun createDescriptorMangler(): KotlinMangler.DescriptorMangler {
-        return KonanManglerDesc
-    }
-
     override fun createIrMangler(): KotlinMangler.IrMangler {
         return KonanManglerIr
     }
@@ -62,7 +57,7 @@ class Fir2IrNativeResultsConverter(testServices: TestServices) : AbstractFir2IrN
             fir2IrResult.irModuleFragment,
             fir2IrResult.pluginContext,
             diagnosticReporter = diagnosticReporter,
-            descriptorMangler = manglers.descriptorMangler,
+            descriptorMangler = null,
             irMangler = manglers.irMangler,
             firMangler = manglers.firMangler,
         )