diff --git a/plugins/kotlin-serialization/kotlin-serialization-compiler/testData/codegen/Basic.ir.txt b/plugins/kotlin-serialization/kotlin-serialization-compiler/testData/codegen/Basic.ir.txt
index 501d7c624ef..f9193a241bd 100644
--- a/plugins/kotlin-serialization/kotlin-serialization-compiler/testData/codegen/Basic.ir.txt
+++ b/plugins/kotlin-serialization/kotlin-serialization-compiler/testData/codegen/Basic.ir.txt
@@ -621,6 +621,7 @@ public final class OptionalUser : java/lang/Object {
         LABEL (L0)
           ALOAD (0)
           ACONST_NULL
+          CHECKCAST
           ICONST_1
           ACONST_NULL
           INVOKESPECIAL (OptionalUser, <init>, (LUser;ILkotlin/jvm/internal/DefaultConstructorMarker;)V)
@@ -964,4 +965,4 @@ public final class User : java/lang/Object {
     public final java.lang.String getFirstName()
 
     public final java.lang.String getLastName()
-}
+}
\ No newline at end of file