diff --git a/docs/configuration.rst b/docs/configuration.rst
index af61df7..41779f0 100644
--- a/docs/configuration.rst
+++ b/docs/configuration.rst
@@ -51,6 +51,9 @@ For other use cases, you can customize these configuration options in your ``con
    Default: The path from the `READTHEDOCS_CANONICAL_URL <https://docs.readthedocs.com/platform/stable/reference/environment-variables.html#envvar-READTHEDOCS_CANONICAL_URL>`__ environment variable.
    In case that variables is not defined, it defaults to ``/en/latest/``.
 
+   You can use `{language}` substitution to include the build's language urified (lowercased, with `_` and `@` converted
+   to `-`).
+
    Type: string
 
    .. warning::
diff --git a/notfound/extension.py b/notfound/extension.py
index 2e2b5ee..5e1297d 100644
--- a/notfound/extension.py
+++ b/notfound/extension.py
@@ -76,7 +76,11 @@ def finalize_media(app, pagename, templatename, context, doctree):
     :type doctree: docutils.nodes.document
     """
 
-    default_baseuri = app.config.notfound_urls_prefix or '/'
+    language_uri = app.config.language.lower().replace('_', '-').replace('@', '-')
+    if app.config.notfound_urls_prefix:
+        default_baseuri = app.config.notfound_urls_prefix.format(language=language_uri)
+    else:
+        default_baseuri = '/'
 
     # https://github.com/sphinx-doc/sphinx/blob/v7.2.3/sphinx/builders/html/__init__.py#L1024-L1036
     def pathto(otheruri: str, resource: bool = False, baseuri: str = default_baseuri):
@@ -295,6 +299,12 @@ def validate_configs(app, *args, **kwargs):
         message = 'notfound_urls_prefix should start and end with "/" (slash)'
         warnings.warn(message, UserWarning, stacklevel=2)
 
+    if notfound_urls_prefix != default and notfound_urls_prefix:
+        no_language = notfound_urls_prefix.replace('{language}', '')
+        if '{' in no_language and '}' in no_language:
+            message = 'notfound_urls_prefix supports only "{language}" substitution'
+            warnings.warn(message, UserWarning, stacklevel=2)
+
 
 def setup(app):
     default_context = {
diff --git a/tests/test_urls.py b/tests/test_urls.py
index 21ffb53..d028319 100644
--- a/tests/test_urls.py
+++ b/tests/test_urls.py
@@ -135,8 +135,9 @@ def test_pagename_setting(app, status, warning):
 @pytest.mark.sphinx(
     srcdir=srcdir,
     confoverrides={
-        'notfound_urls_prefix': '/language/version/',
+        'notfound_urls_prefix': '/{language}/version/',
         'html_theme': 'alabaster',
+        'language': 'pt_BR',
     },
 )
 def test_urls_prefix_setting(app, status, warning):
@@ -154,22 +155,22 @@ def test_urls_prefix_setting(app, status, warning):
     if sphinx.version_info < (7, 4):
         alt = "Logo"
     else:
-        alt = "Logo of Python"
+        alt = "Logo de Python"
 
     chunks = [
         # sidebar URLs
-        '<h1 class="logo"><a href="/language/version/index.html">Python</a></h1>',
-        '<form class="search" action="/language/version/search.html" method="get">',
-        '<li><a href="/language/version/index.html">Documentation overview</a><ul>',
+        '<h1 class="logo"><a href="/pt-br/version/index.html">Python</a></h1>',
+        '<form class="search" action="/pt-br/version/search.html" method="get">',
+        '<li><a href="/pt-br/version/index.html">Documentation overview</a><ul>',
 
         # favicon and logo
-        f'<link rel="{cssclass}icon" href="/language/version/_static/favicon.png"/>',
-        f'<img class="logo" src="/language/version/_static/logo.svg" alt="{alt}"/>',
+        f'<link rel="{cssclass}icon" href="/pt-br/version/_static/favicon.png"/>',
+        f'<img class="logo" src="/pt-br/version/_static/logo.svg" alt="{alt}"/>',
 
         # resources
-        _get_css_html_link_tag(app, 'language', 'version', 'alabaster.css'),
-        _get_css_html_link_tag(app, 'language', 'version', 'pygments.css'),
-        '<link rel="stylesheet" href="/language/version/_static/custom.css" type="text/css" />',
+        _get_css_html_link_tag(app, 'pt-br', 'version', 'alabaster.css'),
+        _get_css_html_link_tag(app, 'pt-br', 'version', 'pygments.css'),
+        '<link rel="stylesheet" href="/pt-br/version/_static/custom.css" type="text/css" />',
     ]
 
     for chunk in chunks: