diff --git a/CHANGELOG b/CHANGELOG
index b0e4450..6afa19b 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -5,6 +5,8 @@
   [bug=2097262]
 * Restored the English documentation to the source distribution.
   [bug=2097237]
+* Fixed a regression where HTMLFormatter and XMLFormatter were not
+  propagating the indent parameter to the superconstructor. [bug=2097272]
 
 = 4.13.0 (20250202)
 
diff --git a/bs4/builder/__init__.py b/bs4/builder/__init__.py
index 7225f30..5f2b38d 100644
--- a/bs4/builder/__init__.py
+++ b/bs4/builder/__init__.py
@@ -192,17 +192,11 @@ class TreeBuilder(object):
      doesn't keep track of this information, then store_line_numbers
      is irrelevant.
 
-    :param attribute_dict_class: A Tag's attribute values (available
-      as tag.attrs) willl be stored in an instance of this class.
-      The default is Beautiful Soup's built-in `AttributeDict` class and
-      you will probably never need to change it.
-
     :param attribute_dict_class: The value of a multi-valued attribute
       (such as HTML's 'class') willl be stored in an instance of this
       class.  The default is Beautiful Soup's built-in
       `AttributeValueList`, which is a normal Python list, and you
       will probably never need to change it.
-
     """
 
     USE_DEFAULT: Any = object()  #: :meta private:
diff --git a/bs4/formatter.py b/bs4/formatter.py
index 34c3351..bfa0876 100644
--- a/bs4/formatter.py
+++ b/bs4/formatter.py
@@ -83,7 +83,7 @@ class Formatter(EntitySubstitution):
         void_element_close_prefix: str = "/",
         cdata_containing_tags: Optional[Set[str]] = None,
         empty_attributes_are_booleans: bool = False,
-        indent: int = 1,
+        indent: Union[int,str] = 1,
     ):
         r"""Constructor.
 
@@ -201,7 +201,7 @@ class HTMLFormatter(Formatter):
         void_element_close_prefix: str = "/",
         cdata_containing_tags: Optional[Set[str]] = None,
         empty_attributes_are_booleans: bool = False,
-        indent: int = 1,
+        indent: Union[int,str] = 1,
     ):
         super(HTMLFormatter, self).__init__(
             self.HTML,
@@ -209,6 +209,7 @@ class HTMLFormatter(Formatter):
             void_element_close_prefix,
             cdata_containing_tags,
             empty_attributes_are_booleans,
+            indent=indent
         )
 
 
@@ -223,7 +224,7 @@ class XMLFormatter(Formatter):
         void_element_close_prefix: str = "/",
         cdata_containing_tags: Optional[Set[str]] = None,
         empty_attributes_are_booleans: bool = False,
-        indent: int = 1,
+        indent: Union[int,str] = 1,
     ):
         super(XMLFormatter, self).__init__(
             self.XML,
@@ -231,6 +232,7 @@ class XMLFormatter(Formatter):
             void_element_close_prefix,
             cdata_containing_tags,
             empty_attributes_are_booleans,
+            indent=indent,
         )
 
 
diff --git a/bs4/tests/test_formatter.py b/bs4/tests/test_formatter.py
index a2c64cf..0b840c5 100644
--- a/bs4/tests/test_formatter.py
+++ b/bs4/tests/test_formatter.py
@@ -109,6 +109,17 @@ class TestFormatter(SoupTest):
         formatter = Formatter()
         assert formatter.indent == " "
 
+    @pytest.mark.parametrize("formatter,expect",
+        [
+            (HTMLFormatter(indent=1), "<p>\n a\n</p>\n"),
+            (HTMLFormatter(indent=2), "<p>\n  a\n</p>\n"),
+            (XMLFormatter(indent=1), "<p>\n a\n</p>\n"),
+            (XMLFormatter(indent="\t"), "<p>\n\ta\n</p>\n"),
+        ]                             )
+    def test_indent_subclasses(self, formatter, expect):
+        soup = self.soup("<p>a</p>")
+        assert expect == soup.p.prettify(formatter=formatter)
+
     @pytest.mark.parametrize(
         "s,expect_html,expect_html5",
         [
diff --git a/tox.ini b/tox.ini
index 7b74349..d0ec26d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -15,7 +15,7 @@ deps = lxml
      packaging
      soupsieve>=2.6
      pytest>=6
-     typing_extensions
+     typing_extensions>=4.0.0
 commands = pytest {tty:--color=yes} {posargs}
 
 [testenv:docs]