diff --git a/platform/lang-impl/src/com/intellij/util/indexing/FileBasedIndexImpl.java b/platform/lang-impl/src/com/intellij/util/indexing/FileBasedIndexImpl.java
index 42c192aca309..7bbd2f386691 100644
--- a/platform/lang-impl/src/com/intellij/util/indexing/FileBasedIndexImpl.java
+++ b/platform/lang-impl/src/com/intellij/util/indexing/FileBasedIndexImpl.java
@@ -16,6 +16,7 @@
 
 package com.intellij.util.indexing;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.intellij.AppTopics;
 import com.intellij.history.LocalHistory;
 import com.intellij.ide.PowerSaveMode;
@@ -242,16 +243,7 @@ public class FileBasedIndexImpl extends FileBasedIndex implements BaseComponent,
       }
 
       private void rebuildAllIndices() {
-        waitUntilIndicesAreInitialized();
-        IndexingStamp.flushCaches();
-        for (ID<?, ?> indexId : getState().getIndexIDs()) {
-          try {
-            clearIndex(indexId);
-          }
-          catch (StorageException e) {
-            LOG.info(e);
-          }
-        }
+        doClearIndices();
         scheduleIndexRebuild("File type change");
       }
     });
@@ -281,6 +273,20 @@ public class FileBasedIndexImpl extends FileBasedIndex implements BaseComponent,
     myConnection.subscribe(VirtualFileManager.VFS_CHANGES, myChangedFilesCollector);
   }
 
+  @VisibleForTesting
+  void doClearIndices() {
+    waitUntilIndicesAreInitialized();
+    IndexingStamp.flushCaches();
+    for (ID<?, ?> indexId : getState().getIndexIDs()) {
+      try {
+        clearIndex(indexId);
+      }
+      catch (StorageException e) {
+        LOG.info(e);
+      }
+    }
+  }
+
   public static boolean isProjectOrWorkspaceFile(@NotNull VirtualFile file, @Nullable FileType fileType) {
     return ProjectCoreUtil.isProjectOrWorkspaceFile(file, fileType);
   }
diff --git a/platform/lang-impl/testSources/com/intellij/util/indexing/IndexingTestUtils.kt b/platform/lang-impl/testSources/com/intellij/util/indexing/IndexingTestUtils.kt
new file mode 100644
index 000000000000..865d5b342f3a
--- /dev/null
+++ b/platform/lang-impl/testSources/com/intellij/util/indexing/IndexingTestUtils.kt
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2000-2017 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.util.indexing
+
+/**
+ * @author traff
+ */
+fun FileBasedIndex.clearIndices() {
+  (this as FileBasedIndexImpl).doClearIndices()
+}
\ No newline at end of file