diff --git a/CHANGES.rst b/CHANGES.rst
index 1dc0dca..dbb8dbc 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -4,6 +4,8 @@ Change Log
 Unreleased
 ----------
 
+- Switch from unmaintained ``appdirs`` to the replacement ``platformdirs``.
+
 1.4.1 (2021/09/10)
 ------------------
 
diff --git a/docstrfmt/util.py b/docstrfmt/util.py
index a8ec4fc..a13fb80 100644
--- a/docstrfmt/util.py
+++ b/docstrfmt/util.py
@@ -4,16 +4,16 @@
 from copy import copy
 from pathlib import Path
 
-from appdirs import user_cache_dir
 from docutils.parsers.rst.states import ParserError
 from docutils.utils import roman
+from platformdirs import user_cache_path
 
 from .const import __version__
 
 
 class FileCache:
     def __init__(self, context):
-        self.cache_dir = Path(user_cache_dir("docstrfmt", version=__version__))
+        self.cache_dir = user_cache_path("docstrfmt", version=__version__)
         self.context = context
         self.cache = self.read_cache()
 
diff --git a/setup.py b/setup.py
index 098d345..468a66a 100644
--- a/setup.py
+++ b/setup.py
@@ -49,11 +49,11 @@
     },
     extras_require=extras_requires,
     install_requires=[
-        "appdirs",
         "black>=19.10b0",
         "click<8.0.0",
         "docutils",
         "libcst",
+        "platformdirs",
         "sphinx>=2.4.0",
         "tabulate",
         "toml",