diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/FirConstChecks.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/FirConstChecks.kt
index b5c49d0b40d..a760d6e7d8a 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/FirConstChecks.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/FirConstChecks.kt
@@ -134,7 +134,7 @@ internal fun checkConstantArguments(
 
                         if (calleeReference.name == OperatorNameConventions.PLUS
                             && expClassId != receiverClassId
-                            && (expClassId !in StandardClassIds.primitiveTypesAndString || receiverClassId !in StandardClassIds.primitiveTypesAndString)
+                            && (expClassId !in StandardClassIds.constantAllowedTypes || receiverClassId !in StandardClassIds.constantAllowedTypes)
                         ) {
                             return ConstantArgumentKind.NOT_CONST
                         }
diff --git a/compiler/testData/codegen/box/constants/foldingBinaryOpsUnsignedConst.kt b/compiler/testData/codegen/box/constants/foldingBinaryOpsUnsignedConst.kt
index 8d44e0b64af..f0d27e0b0b7 100644
--- a/compiler/testData/codegen/box/constants/foldingBinaryOpsUnsignedConst.kt
+++ b/compiler/testData/codegen/box/constants/foldingBinaryOpsUnsignedConst.kt
@@ -1,5 +1,4 @@
 // WITH_RUNTIME
-// IGNORE_BACKEND_FIR: JVM_IR
 
 const val a = "INT " + 0x8fffffffU
 const val b = "BYTE " + 0x8ffU
diff --git a/core/compiler.common/src/org/jetbrains/kotlin/name/StandardClassIds.kt b/core/compiler.common/src/org/jetbrains/kotlin/name/StandardClassIds.kt
index 7d361c39708..fe5859e1c70 100644
--- a/core/compiler.common/src/org/jetbrains/kotlin/name/StandardClassIds.kt
+++ b/core/compiler.common/src/org/jetbrains/kotlin/name/StandardClassIds.kt
@@ -68,7 +68,6 @@ object StandardClassIds {
         Byte, Short, Int, Long,
         Float, Double
     )
-    val primitiveTypesAndString = primitiveTypes + String
 
     val primitiveArrayTypeByElementType = primitiveTypes.associate { id -> id to id.shortClassName.primitiveArrayId() }
     val elementTypeByPrimitiveArrayType = primitiveArrayTypeByElementType.inverseMap()
@@ -77,6 +76,8 @@ object StandardClassIds {
     val unsignedArrayTypeByElementType = unsignedTypes.associate { id -> id to id.shortClassName.primitiveArrayId() }
     val elementTypeByUnsignedArrayType = unsignedArrayTypeByElementType.inverseMap()
 
+    val constantAllowedTypes = primitiveTypes + unsignedTypes + String
+
     val Continuation =
         ClassId(StandardNames.COROUTINES_PACKAGE_FQ_NAME_RELEASE, StandardNames.CONTINUATION_INTERFACE_FQ_NAME_RELEASE.shortName())