diff --git a/java/java-tests/testSrc/com/intellij/util/indexing/MultiProjectIndexTest.kt b/java/java-tests/testSrc/com/intellij/util/indexing/MultiProjectIndexTest.kt
index bd118721873f..b52394738d31 100644
--- a/java/java-tests/testSrc/com/intellij/util/indexing/MultiProjectIndexTest.kt
+++ b/java/java-tests/testSrc/com/intellij/util/indexing/MultiProjectIndexTest.kt
@@ -1,8 +1,9 @@
-// Copyright 2000-2021 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.util.indexing
 
 import com.intellij.find.ngrams.TrigramIndex
 import com.intellij.ide.plugins.loadExtensionWithText
+import com.intellij.openapi.extensions.InternalIgnoreDependencyViolation
 import com.intellij.openapi.module.JavaModuleType
 import com.intellij.openapi.project.DumbService
 import com.intellij.openapi.project.Project
@@ -89,7 +90,8 @@ class MultiProjectIndexTest {
   private fun Path.toVirtualFile(): VirtualFile = VirtualFileManager.getInstance().refreshAndFindFileByNioPath(this)!!
 }
 
-class CountingTestExtension : FileBasedIndexInfrastructureExtension {
+@InternalIgnoreDependencyViolation
+internal class CountingTestExtension : FileBasedIndexInfrastructureExtension {
   val stubCounter = AtomicInteger()
   val trigramCounter = AtomicInteger()
   val commonBundledFileCounter = AtomicInteger()