diff --git a/CHANGES.rst b/CHANGES.rst
index 3e416b5..bc967dc 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -5,7 +5,8 @@ Changelog
 2.0.3 (unreleased)
 ------------------
 
-- Nothing changed yet.
+- Fix ``ModuleNotFoundError`` when trying to import ``safe_name`` from ``setuptools`` 80.2.0 or higher.
+  [maurits]
 
 
 2.0.2 (2024-04-24)
diff --git a/src/mr/developer/extension.py b/src/mr/developer/extension.py
index d37594a..4e285ae 100644
--- a/src/mr/developer/extension.py
+++ b/src/mr/developer/extension.py
@@ -1,5 +1,4 @@
 from mr.developer.common import memoize, WorkingCopies, Config, get_workingcopytypes
-from setuptools.package_index import safe_name
 import logging
 import os
 import re
@@ -11,6 +10,17 @@
 logger = logging.getLogger("mr.developer")
 
 
+def safe_name(name: str) -> str:
+    """Convert an arbitrary string to a standard distribution name
+
+    Any runs of non-alphanumeric/. characters are replaced with a single '-'.
+
+    This is copied from pkg_resources.safe_name.
+    (formerly setuptools.package_index.safe_name)
+    """
+    return re.sub('[^A-Za-z0-9.]+', '-', name)
+
+
 class Source(dict):
     def exists(self):
         return os.path.exists(self['path'])