diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrClassifierStorage.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrClassifierStorage.kt
index 5c45044e836..38d40d5674e 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrClassifierStorage.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrClassifierStorage.kt
@@ -426,7 +426,7 @@ class Fir2IrClassifierStorage(
         val irTypeParameter = with(typeParameter) {
             convertWithOffsets { startOffset, endOffset ->
                 signatureComposer.composeTypeParameterSignature(
-                    typeParameter, index, ownerSymbol.signature
+                    index, ownerSymbol.signature
                 )?.let { signature ->
                     if (ownerSymbol is IrClassifierSymbol) {
                         symbolTable.declareGlobalTypeParameter(
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 98618c776a7..902edb06314 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
@@ -11,6 +11,7 @@ import org.jetbrains.kotlin.fir.backend.generators.CallAndReferenceGenerator
 import org.jetbrains.kotlin.fir.backend.generators.DelegatedMemberGenerator
 import org.jetbrains.kotlin.fir.backend.generators.FakeOverrideGenerator
 import org.jetbrains.kotlin.fir.resolve.ScopeSession
+import org.jetbrains.kotlin.fir.signaturer.FirBasedSignatureComposer
 import org.jetbrains.kotlin.ir.IrLock
 import org.jetbrains.kotlin.ir.declarations.IrFactory
 import org.jetbrains.kotlin.ir.linkage.IrProvider
@@ -33,7 +34,7 @@ interface Fir2IrComponents {
     val declarationStorage: Fir2IrDeclarationStorage
 
     val typeConverter: Fir2IrTypeConverter
-    val signatureComposer: Fir2IrSignatureComposer
+    val signatureComposer: FirBasedSignatureComposer
     val visibilityConverter: Fir2IrVisibilityConverter
 
     val annotationGenerator: AnnotationGenerator
diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrSignatureComposer.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrSignatureComposer.kt
deleted file mode 100644
index dc6fce75654..00000000000
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrSignatureComposer.kt
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- * Copyright 2010-2022 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.fir.declarations.FirDeclaration
-import org.jetbrains.kotlin.fir.declarations.FirProperty
-import org.jetbrains.kotlin.fir.declarations.FirTypeParameter
-import org.jetbrains.kotlin.fir.symbols.ConeClassLikeLookupTag
-import org.jetbrains.kotlin.ir.util.IdSignature
-
-interface Fir2IrSignatureComposer {
-    val mangler: FirMangler
-    fun composeSignature(
-        declaration: FirDeclaration,
-        containingClass: ConeClassLikeLookupTag? = null,
-        forceTopLevelPrivate: Boolean = false,
-        forceExpect: Boolean = false,
-    ): IdSignature?
-
-    fun composeAccessorSignature(
-        property: FirProperty,
-        isSetter: Boolean,
-        containingClass: ConeClassLikeLookupTag? = null,
-        forceTopLevelPrivate: Boolean = false
-    ): IdSignature?
-
-    fun composeTypeParameterSignature(typeParameter: FirTypeParameter, index: Int, containerSignature: IdSignature?): IdSignature?
-    fun withFileSignature(sig: IdSignature.FileSignature, body: () -> Unit)
-}
diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/WrappedDescriptorSignatureComposer.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/WrappedDescriptorSignatureComposer.kt
index 8727e6879bd..674e7bbbf45 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/WrappedDescriptorSignatureComposer.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/WrappedDescriptorSignatureComposer.kt
@@ -5,16 +5,17 @@
 
 package org.jetbrains.kotlin.fir.backend
 
+import org.jetbrains.kotlin.fir.signaturer.FirBasedSignatureComposer
 import org.jetbrains.kotlin.ir.util.IdSignature
 import org.jetbrains.kotlin.ir.util.IdSignatureComposer
 
 class WrappedDescriptorSignatureComposer(
     private val delegate: IdSignatureComposer,
-    private val firComposer: Fir2IrSignatureComposer
+    private val firComposer: FirBasedSignatureComposer
 ) : IdSignatureComposer by delegate {
     override fun withFileSignature(fileSignature: IdSignature.FileSignature, body: () -> Unit) {
         firComposer.withFileSignature(fileSignature) {
             delegate.withFileSignature(fileSignature, body)
         }
     }
-}
\ No newline at end of file
+}
diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/signaturer/FirBasedSignatureComposer.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/signaturer/FirBasedSignatureComposer.kt
index e3aa0478fd8..455b568f66d 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/signaturer/FirBasedSignatureComposer.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/signaturer/FirBasedSignatureComposer.kt
@@ -5,11 +5,9 @@
 
 package org.jetbrains.kotlin.fir.signaturer
 
-import org.jetbrains.kotlin.KtFakeSourceElementKind
 import org.jetbrains.kotlin.backend.common.serialization.mangle.MangleConstant
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.fir.*
-import org.jetbrains.kotlin.fir.backend.Fir2IrSignatureComposer
 import org.jetbrains.kotlin.fir.backend.FirMangler
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertyGetter
@@ -24,10 +22,10 @@ import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
 
 // @NoMutableState -- we'll restore this annotation once we get rid of withFileSignature().
-class FirBasedSignatureComposer(override val mangler: FirMangler) : Fir2IrSignatureComposer {
+class FirBasedSignatureComposer(val mangler: FirMangler) {
     private var fileSignature: IdSignature.FileSignature? = null
 
-    override fun withFileSignature(sig: IdSignature.FileSignature, body: () -> Unit) {
+    fun withFileSignature(sig: IdSignature.FileSignature, body: () -> Unit) {
         fileSignature = sig
         body()
         fileSignature = null
@@ -86,11 +84,11 @@ class FirBasedSignatureComposer(override val mangler: FirMangler) : Fir2IrSignat
         }
     }
 
-    override fun composeSignature(
+    fun composeSignature(
         declaration: FirDeclaration,
-        containingClass: ConeClassLikeLookupTag?,
-        forceTopLevelPrivate: Boolean,
-        forceExpect: Boolean,
+        containingClass: ConeClassLikeLookupTag? = null,
+        forceTopLevelPrivate: Boolean = false,
+        forceExpect: Boolean = false,
     ): IdSignature? {
         if (declaration is FirAnonymousObject || declaration is FirAnonymousFunction) return null
         if (declaration is FirRegularClass && declaration.classId.isLocal) return null
@@ -169,8 +167,7 @@ class FirBasedSignatureComposer(override val mangler: FirMangler) : Fir2IrSignat
         }
     }
 
-    override fun composeTypeParameterSignature(
-        typeParameter: FirTypeParameter,
+    fun composeTypeParameterSignature(
         index: Int,
         containerSignature: IdSignature?
     ): IdSignature? {
@@ -181,11 +178,11 @@ class FirBasedSignatureComposer(override val mangler: FirMangler) : Fir2IrSignat
         )
     }
 
-    override fun composeAccessorSignature(
+    fun composeAccessorSignature(
         property: FirProperty,
         isSetter: Boolean,
-        containingClass: ConeClassLikeLookupTag?,
-        forceTopLevelPrivate: Boolean
+        containingClass: ConeClassLikeLookupTag? = null,
+        forceTopLevelPrivate: Boolean = false
     ): IdSignature? {
         val propSig: IdSignature.CommonSignature
         val fileSig: IdSignature.FileSignature?