diff --git a/CHANGES b/CHANGES
index 5ab2aad22..cd640cb6b 100644
--- a/CHANGES
+++ b/CHANGES
@@ -51,6 +51,8 @@ Deprecated
   is_meta_keywords()``
 * The ``suffix`` argument of ``env.doc2path()`` is deprecated.
 * The string style ``base`` argument of ``env.doc2path()`` is deprecated.
+* The fallback to allow omitting the ``filename`` argument from an overridden
+  ``IndexBuilder.feed()`` method is deprecated.
 * ``sphinx.addnodes.abbreviation``
 * ``sphinx.application.Sphinx._setting_up_extension``
 * ``sphinx.config.check_unicode()``
diff --git a/doc/extdev/index.rst b/doc/extdev/index.rst
index 34e2fd18a..67ab1afa6 100644
--- a/doc/extdev/index.rst
+++ b/doc/extdev/index.rst
@@ -242,6 +242,12 @@ The following is a list of deprecated interfaces.
      - 4.0
      - N/A
 
+   * - Omitting the ``filename`` argument in an overriddent
+       ``IndexBuilder.feed()`` method.
+     - 2.0
+     - 4.0
+     - ``IndexBuilder.feed(docname, filename, title, doctree)``
+
    * - ``sphinx.writers.latex.LaTeXTranslator.babel_defmacro()``
      - 2.0
      - 4.0
diff --git a/sphinx/builders/html.py b/sphinx/builders/html.py
index 79f259b24..e1afe963e 100644
--- a/sphinx/builders/html.py
+++ b/sphinx/builders/html.py
@@ -31,7 +31,7 @@ from six import text_type
 from sphinx import package_dir, __display_version__
 from sphinx.application import ENV_PICKLE_FILENAME
 from sphinx.builders import Builder
-from sphinx.deprecation import RemovedInSphinx30Warning
+from sphinx.deprecation import RemovedInSphinx30Warning, RemovedInSphinx40Warning
 from sphinx.environment.adapters.asset import ImageAdapter
 from sphinx.environment.adapters.indexentries import IndexEntries
 from sphinx.environment.adapters.toctree import TocTree
@@ -976,6 +976,12 @@ class StandaloneHTMLBuilder(Builder):
             except TypeError:
                 # fallback for old search-adapters
                 self.indexer.feed(pagename, title, doctree)  # type: ignore
+                indexer_name = self.indexer.__class__.__name__
+                warnings.warn(
+                    'The %s.feed() method signature is deprecated. Update to '
+                    '%s.feed(docname, filename, title, doctree).' % (
+                        indexer_name, indexer_name),
+                    RemovedInSphinx40Warning)
 
     def _get_local_toctree(self, docname, collapse=True, **kwds):
         # type: (str, bool, Any) -> str
diff --git a/sphinx/locale/__init__.py b/sphinx/locale/__init__.py
index 9e78879d0..42b8d06c0 100644
--- a/sphinx/locale/__init__.py
+++ b/sphinx/locale/__init__.py
@@ -190,8 +190,6 @@ def init(locale_dirs, language, catalog='sphinx', namespace='general'):
         translator = NullTranslations()
         has_translation = False
     translators[(namespace, catalog)] = translator
-    if hasattr(translator, 'ugettext'):
-        translator.gettext = translator.ugettext  # type: ignore
     return translator, has_translation
 
 
diff --git a/tests/test_directive_code.py b/tests/test_directive_code.py
index 34e3e525c..43d9ff99c 100644
--- a/tests/test_directive_code.py
+++ b/tests/test_directive_code.py
@@ -356,7 +356,7 @@ def test_code_block_emphasize_latex(app, status, warning):
     latex = (app.outdir / 'Python.tex').text(encoding='utf-8').replace('\r\n', '\n')
     includes = '\\fvset{hllines={, 5, 6, 13, 14, 15, 24, 25, 26, 27,}}%\n'
     assert includes in latex
-    includes = '\\end{sphinxVerbatim}\n\sphinxresetverbatimhllines\n'
+    includes = '\\end{sphinxVerbatim}\n\\sphinxresetverbatimhllines\n'
     assert includes in latex