diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxingFrame.kt b/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxingFrame.kt
index 08b5e26ca3d..114a6bd3d74 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxingFrame.kt
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxingFrame.kt
@@ -10,12 +10,13 @@ import org.jetbrains.org.objectweb.asm.tree.analysis.BasicValue
 import org.jetbrains.org.objectweb.asm.tree.analysis.Frame
 import org.jetbrains.org.objectweb.asm.tree.analysis.Interpreter
 
-class BoxingFrame(nLocals: Int, nStack: Int, private val boxingInterpreter: BoxingInterpreter) : Frame<BasicValue>(nLocals, nStack) {
+class BoxingFrame(nLocals: Int, nStack: Int) : Frame<BasicValue>(nLocals, nStack) {
     override fun merge(frame: Frame<out BasicValue>, interpreter: Interpreter<BasicValue>): Boolean {
         if (stackSize != frame.stackSize) {
             throw AnalyzerException(null, "Incompatible stack heights")
         }
 
+        val boxingInterpreter = interpreter as BoxingInterpreter
         var changed = false
         for (i in 0 until locals) {
             val local = getLocal(i)
diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/RedundantBoxingMethodTransformer.kt b/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/RedundantBoxingMethodTransformer.kt
index a08f2b016ed..c53fee12c79 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/RedundantBoxingMethodTransformer.kt
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/RedundantBoxingMethodTransformer.kt
@@ -44,7 +44,7 @@ class RedundantBoxingMethodTransformer(private val generationState: GenerationSt
         val interpreter = RedundantBoxingInterpreter(node, generationState)
         val analyzer = FastMethodAnalyzer<BasicValue>(
             internalClassName, node, interpreter, pruneExceptionEdges = false
-        ) { nLocals, nStack -> BoxingFrame(nLocals, nStack, interpreter) }
+        ) { nLocals, nStack -> BoxingFrame(nLocals, nStack) }
         val frames = analyzer.analyze()
 
         interpretPopInstructionsForBoxedValues(interpreter, node, frames)