diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/ClassMemberGenerator.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/ClassMemberGenerator.kt
index f7c745c3bad..d589327bcbc 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/ClassMemberGenerator.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/ClassMemberGenerator.kt
@@ -125,14 +125,14 @@ internal class ClassMemberGenerator(
                         irFunction.body = IrSyntheticBodyImpl(startOffset, endOffset, kind)
                     }
                     irFunction.parent is IrClass && irFunction.parentAsClass.isData -> {
-                        val classId = firFunction?.symbol?.dispatchReceiverClassOrNull()?.classId
+                        val lookupTag = firFunction?.symbol?.dispatchReceiverClassOrNull()
                         when {
                             DataClassMembersGenerator.isComponentN(irFunction) ->
                                 firFunction?.body?.let { irFunction.body = visitor.convertToIrBlockBody(it) }
-                                    ?: DataClassMembersGenerator(components).generateDataClassComponentBody(irFunction, classId!!)
+                                    ?: DataClassMembersGenerator(components).generateDataClassComponentBody(irFunction, lookupTag!!)
                             DataClassMembersGenerator.isCopy(irFunction) ->
                                 firFunction?.body?.let { irFunction.body = visitor.convertToIrBlockBody(it) }
-                                    ?: DataClassMembersGenerator(components).generateDataClassCopyBody(irFunction, classId!!)
+                                    ?: DataClassMembersGenerator(components).generateDataClassCopyBody(irFunction, lookupTag!!)
                             else ->
                                 irFunction.body = firFunction?.body?.let { visitor.convertToIrBlockBody(it) }
                         }
diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/DataClassMembersGenerator.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/DataClassMembersGenerator.kt
index 0a57abffb52..c5e3a584bc6 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/DataClassMembersGenerator.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/DataClassMembersGenerator.kt
@@ -16,7 +16,9 @@ import org.jetbrains.kotlin.fir.declarations.builder.buildValueParameter
 import org.jetbrains.kotlin.fir.declarations.impl.FirDeclarationStatusImpl
 import org.jetbrains.kotlin.fir.scopes.unsubstitutedScope
 import org.jetbrains.kotlin.fir.symbols.CallableId
+import org.jetbrains.kotlin.fir.symbols.ConeClassLikeLookupTag
 import org.jetbrains.kotlin.fir.symbols.impl.ConeClassLikeLookupTagImpl
+import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirNamedFunctionSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirVariableSymbol
 import org.jetbrains.kotlin.fir.types.ConeStarProjection
@@ -50,20 +52,24 @@ import org.jetbrains.kotlin.name.Name
 class DataClassMembersGenerator(val components: Fir2IrComponents) {
 
     fun generateInlineClassMembers(klass: FirClass<*>, irClass: IrClass): List<FirDeclaration> =
-        MyDataClassMethodsGenerator(irClass, klass.symbol.classId, IrDeclarationOrigin.GENERATED_INLINE_CLASS_MEMBER).generate(klass)
+        MyDataClassMethodsGenerator(irClass, klass.symbol.toLookupTag(), IrDeclarationOrigin.GENERATED_INLINE_CLASS_MEMBER).generate(klass)
 
     fun generateDataClassMembers(klass: FirClass<*>, irClass: IrClass): List<FirDeclaration> =
-        MyDataClassMethodsGenerator(irClass, klass.symbol.classId, IrDeclarationOrigin.GENERATED_DATA_CLASS_MEMBER).generate(klass)
+        MyDataClassMethodsGenerator(irClass, klass.symbol.toLookupTag(), IrDeclarationOrigin.GENERATED_DATA_CLASS_MEMBER).generate(klass)
 
-    fun generateDataClassComponentBody(irFunction: IrFunction, classId: ClassId) =
-        MyDataClassMethodsGenerator(irFunction.parentAsClass, classId, IrDeclarationOrigin.GENERATED_DATA_CLASS_MEMBER)
+    fun generateDataClassComponentBody(irFunction: IrFunction, lookupTag: ConeClassLikeLookupTag) =
+        MyDataClassMethodsGenerator(irFunction.parentAsClass, lookupTag, IrDeclarationOrigin.GENERATED_DATA_CLASS_MEMBER)
             .generateComponentBody(irFunction)
 
-    fun generateDataClassCopyBody(irFunction: IrFunction, classId: ClassId) =
-        MyDataClassMethodsGenerator(irFunction.parentAsClass, classId, IrDeclarationOrigin.GENERATED_DATA_CLASS_MEMBER)
+    fun generateDataClassCopyBody(irFunction: IrFunction, lookupTag: ConeClassLikeLookupTag) =
+        MyDataClassMethodsGenerator(irFunction.parentAsClass, lookupTag, IrDeclarationOrigin.GENERATED_DATA_CLASS_MEMBER)
             .generateCopyBody(irFunction)
 
-    private inner class MyDataClassMethodsGenerator(val irClass: IrClass, val classId: ClassId, val origin: IrDeclarationOrigin) {
+    private inner class MyDataClassMethodsGenerator(
+        val irClass: IrClass,
+        val lookupTag: ConeClassLikeLookupTag,
+        val origin: IrDeclarationOrigin
+    ) {
         private val irDataClassMembersGenerator = object : DataClassMembersGenerator(
             IrGeneratorContextBase(components.irBuiltIns),
             components.symbolTable,
@@ -226,7 +232,7 @@ class DataClassMembersGenerator(val components: Fir2IrComponents) {
             val firFunction = buildSimpleFunction {
                 origin = FirDeclarationOrigin.Synthetic
                 this.name = name
-                this.symbol = FirNamedFunctionSymbol(CallableId(classId, name))
+                this.symbol = FirNamedFunctionSymbol(CallableId(lookupTag.classId, name))
                 this.status = FirDeclarationStatusImpl(Visibilities.Public, Modality.FINAL)
                 this.session = components.session
                 this.returnTypeRef = when (returnType) {
@@ -249,13 +255,11 @@ class DataClassMembersGenerator(val components: Fir2IrComponents) {
                         }
                     )
                 }
-                dispatchReceiverType =
-                    ConeClassLikeLookupTagImpl(classId)
-                        .constructType(
-                            (1..irClass.typeParameters.size).map { ConeStarProjection }.toTypedArray(), isNullable = false
-                        )
+                dispatchReceiverType = lookupTag.constructType(
+                    (1..irClass.typeParameters.size).map { ConeStarProjection }.toTypedArray(), isNullable = false
+                )
             }
-            val signature = if (classId.isLocal) null else components.signatureComposer.composeSignature(firFunction)
+            val signature = if (lookupTag.classId.isLocal) null else components.signatureComposer.composeSignature(firFunction)
             return components.declarationStorage.declareIrSimpleFunction(signature, null) { symbol ->
                 components.irFactory.createFunction(
                     UNDEFINED_OFFSET, UNDEFINED_OFFSET, origin, symbol, name, DescriptorVisibilities.PUBLIC, Modality.OPEN, returnType,