diff --git a/java/java-runtime/src/com/intellij/rt/execution/junit/FileComparisonFailure.java b/java/java-runtime/src/com/intellij/rt/execution/junit/FileComparisonFailure.java
index cccf7b735b7f..c8bbd5b515f0 100644
--- a/java/java-runtime/src/com/intellij/rt/execution/junit/FileComparisonFailure.java
+++ b/java/java-runtime/src/com/intellij/rt/execution/junit/FileComparisonFailure.java
@@ -1,22 +1,10 @@
-/*
- * Copyright 2000-2015 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// 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.rt.execution.junit;
 
 import junit.framework.ComparisonFailure;
 
+import java.io.File;
+
 public class FileComparisonFailure extends ComparisonFailure  {
   private final String myExpected;
   private final String myActual;
@@ -34,6 +22,7 @@ public class FileComparisonFailure extends ComparisonFailure  {
     myExpected = expected;
     myActual = actual;
     myFilePath = expectedFilePath;
+    if (expectedFilePath != null && !new File(expectedFilePath).isFile()) throw new NullPointerException("'expectedFilePath' should point to the existing file or be null");
     myActualFilePath = actualFilePath;
   }