diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/irCodegenUtils.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/irCodegenUtils.kt
index 715e9de38fa..6a72dd8a34f 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/irCodegenUtils.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/irCodegenUtils.kt
@@ -11,7 +11,6 @@ import org.jetbrains.kotlin.backend.common.lower.allOverridden
 import org.jetbrains.kotlin.backend.jvm.JvmBackendContext
 import org.jetbrains.kotlin.backend.jvm.JvmLoweredDeclarationOrigin
 import org.jetbrains.kotlin.backend.jvm.lower.MultifileFacadeFileEntry
-import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns.FQ_NAMES
 import org.jetbrains.kotlin.builtins.jvm.JavaToKotlinClassMap
 import org.jetbrains.kotlin.codegen.*
@@ -33,7 +32,7 @@ import org.jetbrains.kotlin.load.java.JavaVisibilities
 import org.jetbrains.kotlin.load.java.JvmAbi
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.resolve.checkers.ExpectedActualDeclarationChecker
-import org.jetbrains.kotlin.resolve.inline.*
+import org.jetbrains.kotlin.resolve.inline.INLINE_ONLY_ANNOTATION_FQ_NAME
 import org.jetbrains.kotlin.resolve.jvm.jvmSignature.JvmClassSignature
 import org.jetbrains.kotlin.resolve.source.PsiSourceElement
 import org.jetbrains.kotlin.utils.addIfNotNull
@@ -73,8 +72,7 @@ val IrClass.isJvmInterface get() = isAnnotationClass || isInterface
 
 val IrDeclaration.fileParent: IrFile
     get() {
-        val myParent = parent
-        return when (myParent) {
+        return when (val myParent = parent) {
             is IrFile -> myParent
             else -> (myParent as IrDeclaration).fileParent
         }
@@ -103,7 +101,7 @@ fun JvmBackendContext.getSourceMapper(declaration: IrClass): SourceMapper {
 }
 
 val IrType.isExtensionFunctionType: Boolean
-    get() = isFunctionTypeOrSubtype() && hasAnnotation(KotlinBuiltIns.FQ_NAMES.extensionFunctionType)
+    get() = isFunctionTypeOrSubtype() && hasAnnotation(FQ_NAMES.extensionFunctionType)
 
 
 /* Borrowed with modifications from MemberCodegen.java */
@@ -121,23 +119,13 @@ fun writeInnerClass(innerClass: IrClass, typeMapper: IrTypeMapper, context: JvmB
 
 private val NO_FLAG_LOCAL = 0
 
-private val visibilityToAccessFlag = mapOf(
-    Visibilities.PRIVATE to Opcodes.ACC_PRIVATE,
-    Visibilities.PRIVATE_TO_THIS to Opcodes.ACC_PRIVATE,
-    Visibilities.PROTECTED to Opcodes.ACC_PROTECTED,
-    JavaVisibilities.PROTECTED_STATIC_VISIBILITY to Opcodes.ACC_PROTECTED,
-    JavaVisibilities.PROTECTED_AND_PACKAGE to Opcodes.ACC_PROTECTED,
-    Visibilities.PUBLIC to Opcodes.ACC_PUBLIC,
-    Visibilities.INTERNAL to Opcodes.ACC_PUBLIC,
-    Visibilities.LOCAL to NO_FLAG_LOCAL,
-    JavaVisibilities.PACKAGE_VISIBILITY to AsmUtil.NO_FLAG_PACKAGE_PRIVATE
-)
-
 private fun IrDeclaration.getVisibilityAccessFlagForAnonymous(): Int =
     if (isInlineOrContainedInInline(parent as? IrDeclaration)) Opcodes.ACC_PUBLIC else AsmUtil.NO_FLAG_PACKAGE_PRIVATE
 
 fun IrClass.calculateInnerClassAccessFlags(context: JvmBackendContext): Int {
-    val isLambda = superTypes.any { it.safeAs<IrSimpleType>()?.classifier === context.ir.symbols.lambdaClass }
+    val isLambda = superTypes.any {
+        it.safeAs<IrSimpleType>()?.classifier === context.ir.symbols.lambdaClass
+    }
     val visibility = when {
         isLambda -> getVisibilityAccessFlagForAnonymous()
         visibility === Visibilities.LOCAL -> Opcodes.ACC_PUBLIC
@@ -165,18 +153,30 @@ private fun IrClass.innerAccessFlagsForModalityAndKind(): Int {
     return 0
 }
 
-fun IrDeclarationWithVisibility.getVisibilityAccessFlag(kind: OwnerKind? = null): Int =
-    specialCaseVisibility(kind)
-        ?: visibilityToAccessFlag[visibility]
-        ?: throw IllegalStateException("$visibility is not a valid visibility in backend for ${ir2string(this)}")
+fun IrDeclarationWithVisibility.getVisibilityAccessFlag(kind: OwnerKind? = null): Int {
+    specialCaseVisibility(kind)?.let {
+        return it
+    }
+    return when (visibility) {
+        Visibilities.PRIVATE -> Opcodes.ACC_PRIVATE
+        Visibilities.PRIVATE_TO_THIS -> Opcodes.ACC_PRIVATE
+        Visibilities.PROTECTED -> Opcodes.ACC_PROTECTED
+        JavaVisibilities.PROTECTED_STATIC_VISIBILITY -> Opcodes.ACC_PROTECTED
+        JavaVisibilities.PROTECTED_AND_PACKAGE -> Opcodes.ACC_PROTECTED
+        Visibilities.PUBLIC -> Opcodes.ACC_PUBLIC
+        Visibilities.INTERNAL -> Opcodes.ACC_PUBLIC
+        Visibilities.LOCAL -> NO_FLAG_LOCAL
+        JavaVisibilities.PACKAGE_VISIBILITY -> AsmUtil.NO_FLAG_PACKAGE_PRIVATE
+        else -> throw IllegalStateException("$visibility is not a valid visibility in backend for ${ir2string(this)}")
+    }
+}
 
 private fun IrDeclarationWithVisibility.specialCaseVisibility(kind: OwnerKind?): Int? {
 //    if (JvmCodegenUtil.isNonIntrinsicPrivateCompanionObjectInInterface(memberDescriptor)) {
 //        return ACC_PUBLIC
 //    }
-    if (this is IrClass && Visibilities.isPrivate(visibility) &&
-        hasInterfaceParent()
-    ) { // TODO: non-intrinsic
+    if (this is IrClass && Visibilities.isPrivate(visibility) && isCompanion && hasInterfaceParent()) {
+        // TODO: non-intrinsic
         return Opcodes.ACC_PUBLIC
     }
 
diff --git a/compiler/testData/codegen/bytecodeListing/privateNestedClassInInterface.kt b/compiler/testData/codegen/bytecodeListing/privateNestedClassInInterface.kt
new file mode 100644
index 00000000000..c7920bfdb1c
--- /dev/null
+++ b/compiler/testData/codegen/bytecodeListing/privateNestedClassInInterface.kt
@@ -0,0 +1,3 @@
+interface IFoo {
+    private class Nested
+}
\ No newline at end of file
diff --git a/compiler/testData/codegen/bytecodeListing/privateNestedClassInInterface.txt b/compiler/testData/codegen/bytecodeListing/privateNestedClassInInterface.txt
new file mode 100644
index 00000000000..3658eaa6a09
--- /dev/null
+++ b/compiler/testData/codegen/bytecodeListing/privateNestedClassInInterface.txt
@@ -0,0 +1,10 @@
+@kotlin.Metadata
+final class IFoo$Nested {
+    public method <init>(): void
+    private final inner class IFoo$Nested
+}
+
+@kotlin.Metadata
+public interface IFoo {
+    private final inner class IFoo$Nested
+}
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/BytecodeListingTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/BytecodeListingTestGenerated.java
index 4675180bf19..68fe1383b1b 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/BytecodeListingTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/BytecodeListingTestGenerated.java
@@ -144,6 +144,11 @@ public class BytecodeListingTestGenerated extends AbstractBytecodeListingTest {
         runTest("compiler/testData/codegen/bytecodeListing/privateDefaultSetter.kt");
     }
 
+    @TestMetadata("privateNestedClassInInterface.kt")
+    public void testPrivateNestedClassInInterface() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeListing/privateNestedClassInInterface.kt");
+    }
+
     @TestMetadata("samAdapterAndInlinedOne.kt")
     public void testSamAdapterAndInlinedOne() throws Exception {
         runTest("compiler/testData/codegen/bytecodeListing/samAdapterAndInlinedOne.kt");
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBytecodeListingTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBytecodeListingTestGenerated.java
index 64c33c833c7..7d8a0824c57 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBytecodeListingTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBytecodeListingTestGenerated.java
@@ -144,6 +144,11 @@ public class IrBytecodeListingTestGenerated extends AbstractIrBytecodeListingTes
         runTest("compiler/testData/codegen/bytecodeListing/privateDefaultSetter.kt");
     }
 
+    @TestMetadata("privateNestedClassInInterface.kt")
+    public void testPrivateNestedClassInInterface() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeListing/privateNestedClassInInterface.kt");
+    }
+
     @TestMetadata("samAdapterAndInlinedOne.kt")
     public void testSamAdapterAndInlinedOne() throws Exception {
         runTest("compiler/testData/codegen/bytecodeListing/samAdapterAndInlinedOne.kt");