diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/intrinsics/StringPlus.kt b/compiler/backend/src/org/jetbrains/kotlin/codegen/intrinsics/StringPlus.kt
index 45ad737ca7b..9925826ca51 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/intrinsics/StringPlus.kt
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/intrinsics/StringPlus.kt
@@ -43,6 +43,7 @@ class StringPlus : IntrinsicMethod() {
                     )
                 } else {
                     generator.invokeAppend(AsmTypes.JAVA_STRING_TYPE)
+                    //TODO: process constants properly, do not upcast to object
                     generator.invokeAppend(AsmTypes.OBJECT_TYPE)
                     generator.genToString()
                 }