1 files changed, 2 insertions, 14 deletions
diff --git a/sphinx/directives/other.py b/sphinx/directives/other.py
index e4fcc0f5c..fc1631edc 100644
--- a/sphinx/directives/other.py
+++ b/sphinx/directives/other.py
@@ -8,7 +8,7 @@
 
 import re
 from typing import Any, Dict, List
-from typing import cast
+from typing import TYPE_CHECKING, cast
 
 from docutils import nodes
 from docutils.nodes import Element, Node
@@ -18,7 +18,6 @@ from docutils.parsers.rst.directives.misc import Class
 from docutils.parsers.rst.directives.misc import Include as BaseInclude
 
 from sphinx import addnodes
-from sphinx.deprecation import RemovedInSphinx40Warning, deprecated_alias
 from sphinx.domains.changeset import VersionChange  # NOQA  # for compatibility
 from sphinx.locale import _
 from sphinx.util import url_re, docname_join
@@ -26,8 +25,7 @@ from sphinx.util.docutils import SphinxDirective
 from sphinx.util.matching import Matcher, patfilter
 from sphinx.util.nodes import explicit_title_re
 
-if False:
-    # For type annotation
+if TYPE_CHECKING:
     from sphinx.application import Sphinx
 
 
@@ -361,16 +359,6 @@ class Include(BaseInclude, SphinxDirective):
         return super().run()
 
 
-# Import old modules here for compatibility
-from sphinx.domains.index import IndexDirective  # NOQA
-
-deprecated_alias('sphinx.directives.other',
-                 {
-                     'Index': IndexDirective,
-                 },
-                 RemovedInSphinx40Warning)
-
-
 def setup(app: "Sphinx") -> Dict[str, Any]:
     directives.register_directive('toctree', TocTree)
     directives.register_directive('sectionauthor', Author)