diff --git a/oslo_utils/strutils.py b/oslo_utils/strutils.py
index 45badb7c..c406213a 100644
--- a/oslo_utils/strutils.py
+++ b/oslo_utils/strutils.py
@@ -172,21 +172,33 @@ def int_from_bool_as_string(subject: Any) -> int:
     return int(bool_from_string(subject))
 
 
+@overload
 def bool_from_string(
     subject: Any, strict: bool = False, default: bool = False
-) -> bool:
+) -> bool: ...
+
+
+@overload
+def bool_from_string(
+    subject: Any, strict: bool = False, default: bool | None = False
+) -> bool | None: ...
+
+
+def bool_from_string(
+    subject: Any, strict: bool = False, default: bool | None = False
+) -> bool | None:
     """Interpret a subject as a boolean.
 
     A subject can be a boolean, a string or an integer. Boolean type value
     will be returned directly, otherwise the subject will be converted to
     a string. A case-insensitive match is performed such that strings
-    matching 't','true', 'on', 'y', 'yes', or '1' are considered True and,
-    when `strict=False`, anything else returns the value specified by
-    'default'.
+    matching 't', 'true', 'on', 'y', 'yes', or '1' are considered True and,
+    when ``strict=False``, anything else returns the value specified by
+    ``default``.
 
     Useful for JSON-decoded stuff and config file parsing.
 
-    If `strict=True`, unrecognized values, including None, will raise a
+    If ``strict=True``, unrecognized values, including None, will raise a
     ValueError which is useful when parsing values passed in from an API call.
     Strings yielding False are 'f', 'false', 'off', 'n', 'no', or '0'.
     """