diff --git a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/AssignmentGenerator.kt b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/AssignmentGenerator.kt
index 7739421d8a0..47006ecbfd3 100644
--- a/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/AssignmentGenerator.kt
+++ b/compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/AssignmentGenerator.kt
@@ -214,7 +214,7 @@ class AssignmentGenerator(statementGenerator: StatementGenerator) : StatementGen
         return if (getterSymbol != null || setterSymbol != null) {
             val typeArgumentsList =
                 typeArgumentsMap?.let { typeArguments ->
-                    descriptor.typeParameters.map { typeArguments[it]!!.toIrType() }
+                    descriptor.original.typeParameters.map { typeArguments[it]!!.toIrType() }
                 }
             AccessorPropertyLValue(
                 context,