diff --git a/platform/platform-impl/src/com/intellij/openapi/fileTypes/impl/FileTypeManagerImpl.java b/platform/platform-impl/src/com/intellij/openapi/fileTypes/impl/FileTypeManagerImpl.java
index 25a9ac89b882..f0a55eaed2cc 100644
--- a/platform/platform-impl/src/com/intellij/openapi/fileTypes/impl/FileTypeManagerImpl.java
+++ b/platform/platform-impl/src/com/intellij/openapi/fileTypes/impl/FileTypeManagerImpl.java
@@ -1,4 +1,7 @@
 // Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+//
+// Modified by Nikita Iarychenko at 2025 as part of the OpenIDE project (https://openide.ru).
+// Any modifications are available on the same license terms as the original source code.
 package com.intellij.openapi.fileTypes.impl;
 
 import com.intellij.concurrency.ConcurrentCollectionFactory;
@@ -81,7 +84,7 @@ public class FileTypeManagerImpl extends FileTypeManagerEx implements Persistent
   @SuppressWarnings("SpellCheckingInspection")
   @ApiStatus.Internal
   public static final List<String> DEFAULT_IGNORED = List.of("*.pyc", "*.pyo", "*.rbc", "*.yarb", "*~", ".DS_Store", ".git", ".hg",
-                                                      ".mypy_cache", ".pytest_cache", ".ruff_cache",
+                                                      ".idea", ".mypy_cache", ".pytest_cache", ".ruff_cache",
                                                       ".svn", "CVS", "__pycache__", "_svn", "vssver.scc", "vssver2.scc");
 
   static final String FILE_SPEC = "filetypes";