diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/InterfaceDelegationLowering.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/InterfaceDelegationLowering.kt
index 990389ec234..6f7d74837a8 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/InterfaceDelegationLowering.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/InterfaceDelegationLowering.kt
@@ -39,7 +39,7 @@ class InterfaceDelegationLowering(val state: GenerationState) : IrElementTransfo
 
     override fun lower(irClass: IrClass) {
         val descriptor = irClass.descriptor
-        if (!DescriptorUtils.isClass(descriptor)) {
+        if (DescriptorUtils.isInterface(descriptor)) {
             return
         }