diff --git a/json/src/com/intellij/json/psi/impl/JsonTreeChangePreprocessor.java b/json/src/com/intellij/json/psi/impl/JsonTreeChangePreprocessor.java
index 6bb2ee9ee166..0bbf04bd99e4 100644
--- a/json/src/com/intellij/json/psi/impl/JsonTreeChangePreprocessor.java
+++ b/json/src/com/intellij/json/psi/impl/JsonTreeChangePreprocessor.java
@@ -1,85 +1,50 @@
+/*
+ * Copyright 2000-2016 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.
+ */
 package com.intellij.json.psi.impl;
 
 import com.intellij.json.JsonLanguage;
 import com.intellij.json.psi.JsonFile;
+import com.intellij.openapi.project.Project;
 import com.intellij.psi.PsiElement;
-import com.intellij.psi.PsiFile;
 import com.intellij.psi.PsiFileSystemItem;
-import com.intellij.psi.impl.PsiManagerImpl;
-import com.intellij.psi.impl.PsiModificationTrackerImpl;
 import com.intellij.psi.impl.PsiTreeChangeEventImpl;
-import com.intellij.psi.impl.PsiTreeChangePreprocessor;
+import com.intellij.psi.impl.PsiTreeChangePreprocessorBase;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-/**
- * @author Mikhail Golubev
- */
-public class JsonTreeChangePreprocessor implements PsiTreeChangePreprocessor {
-  /**
-   * @see com.intellij.psi.impl.PsiTreeChangePreprocessorBase#treeChanged(com.intellij.psi.impl.PsiTreeChangeEventImpl)
-   */
+public class JsonTreeChangePreprocessor extends PsiTreeChangePreprocessorBase {
+  public JsonTreeChangePreprocessor(@NotNull Project project) {
+    super(project);
+  }
+
   @Override
   public void treeChanged(@NotNull PsiTreeChangeEventImpl event) {
-    if (!(event.getFile() instanceof JsonFile)) return;
-
-    final PsiElement element = event.getParent();
-    if (element == null || !(element.getManager() instanceof PsiManagerImpl)) {
-      return;
-    }
-    final PsiModificationTrackerImpl modificationTracker = (PsiModificationTrackerImpl)element.getManager().getModificationTracker();
-    boolean changedInsideCodeBlock = false;
-
-    switch (event.getCode()) {
-      case BEFORE_CHILDREN_CHANGE:
-        if (event.getParent() instanceof PsiFile) {
-          changedInsideCodeBlock = true;
-          break;
-        }
-
-      case CHILDREN_CHANGED:
-        if (event.isGenericChange()) {
-          return;
-        }
-        changedInsideCodeBlock = isInsideCodeBlock(event.getParent());
-        break;
-
-      case BEFORE_CHILD_ADDITION:
-      case BEFORE_CHILD_REMOVAL:
-      case CHILD_ADDED:
-      case CHILD_REMOVED:
-        changedInsideCodeBlock = isInsideCodeBlock(event.getParent());
-        break;
-
-      case BEFORE_PROPERTY_CHANGE:
-      case PROPERTY_CHANGED:
-        changedInsideCodeBlock = false;
-        break;
-
-      case BEFORE_CHILD_REPLACEMENT:
-      case CHILD_REPLACED:
-        changedInsideCodeBlock = isInsideCodeBlock(event.getParent());
-        break;
-
-      case BEFORE_CHILD_MOVEMENT:
-      case CHILD_MOVED:
-        changedInsideCodeBlock = isInsideCodeBlock(event.getOldParent()) && isInsideCodeBlock(event.getNewParent());
-        break;
-    }
-
-    if (!changedInsideCodeBlock) {
-      modificationTracker.incOutOfCodeBlockModificationCounter();
+    if (event.getFile() instanceof JsonFile) {
+      super.treeChanged(event);
     }
   }
 
-  private boolean isInsideCodeBlock(@Nullable PsiElement element) {
+  @Override
+  protected boolean isInsideCodeBlock(@Nullable PsiElement element) {
     if (element instanceof PsiFileSystemItem) {
       return false;
     }
     if (element == null || element.getParent() == null) {
       return true;
     }
-    // Consider all elements of JSON PSI as externally visible, i.e. they are out of code block
     return !(element.getLanguage() instanceof JsonLanguage);
   }
-}
+}
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