diff --git a/topics/basics/plugin_structure/plugin_extension_points.md b/topics/basics/plugin_structure/plugin_extension_points.md
index 3c4e7bb79..808ff846c 100644
--- a/topics/basics/plugin_structure/plugin_extension_points.md
+++ b/topics/basics/plugin_structure/plugin_extension_points.md
@@ -1,4 +1,4 @@
-<!-- Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license. -->
+<!-- Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license. -->
 
 # Extension Points
 
@@ -58,6 +58,9 @@ Must be one of `IDEA_APPLICATION` for Application (default), `IDEA_PROJECT` for
 
 The plugin that contributes to the extension point will read those properties from the <path>plugin.xml</path> file.
 
+If extension implementations are filtered according to [](indexing_and_psi_stubs.md#dumb-mode), the base class should be
+marked with [`PossiblyDumbAware`](%gh-ic%/platform/core-api/src/com/intellij/openapi/project/PossiblyDumbAware.java) to highlight this.
+
 Base classes for extensions requiring a key:
 
 - [`LanguageExtension`](%gh-ic%/platform/core-api/src/com/intellij/lang/LanguageExtension.java)