1 files changed, 0 insertions, 22 deletions
diff --git a/sphinx/util/compat.py b/sphinx/util/compat.py
index 502edb525..2c38f668b 100644
--- a/sphinx/util/compat.py
+++ b/sphinx/util/compat.py
@@ -9,16 +9,9 @@
 """
 
 import sys
-import warnings
 from typing import Any, Dict
 from typing import TYPE_CHECKING
 
-from docutils.utils import get_source_line
-
-from sphinx import addnodes
-from sphinx.deprecation import RemovedInSphinx40Warning
-from sphinx.transforms import SphinxTransform
-
 if TYPE_CHECKING:
     from sphinx.application import Sphinx
 
@@ -36,22 +29,7 @@ def register_application_for_autosummary(app: "Sphinx") -> None:
         autosummary._app = app
 
 
-class IndexEntriesMigrator(SphinxTransform):
-    """Migrating indexentries from old style (4columns) to new style (5columns)."""
-    default_priority = 700
-
-    def apply(self, **kwargs: Any) -> None:
-        for node in self.document.traverse(addnodes.index):
-            for i, entries in enumerate(node['entries']):
-                if len(entries) == 4:
-                    source, line = get_source_line(node)
-                    warnings.warn('An old styled index node found: %r at (%s:%s)' %
-                                  (node, source, line), RemovedInSphinx40Warning)
-                    node['entries'][i] = entries + (None,)
-
-
 def setup(app: "Sphinx") -> Dict[str, Any]:
-    app.add_transform(IndexEntriesMigrator)
     app.connect('builder-inited', register_application_for_autosummary)
 
     return {