diff --git a/Cheetah/ImportManager.py b/Cheetah/ImportManager.py
index 987ecb69..95cab96f 100644
--- a/Cheetah/ImportManager.py
+++ b/Cheetah/ImportManager.py
@@ -60,14 +60,15 @@ def _os_bootstrap():
     elif 'mac' in names:
         from mac import stat, getcwd
 
-        def join(a, b):
-            if a == '':
-                return b
-            if ':' not in a:
-                a = ':' + a
-            if a[-1:] != ':':
-                a = a + ':'
-            return a + b
+        if join is None:
+            def join(a, b):
+                if a == '':
+                    return b
+                if ':' not in a:
+                    a = ':' + a
+                if a[-1:] != ':':
+                    a = a + ':'
+                return a + b
     else:
         raise ImportError('no os specific module found')
 
diff --git a/docs/news.rst b/docs/news.rst
index 52f01c05..f737cee8 100644
--- a/docs/news.rst
+++ b/docs/news.rst
@@ -8,6 +8,11 @@ Bug fixes:
 
   - Fixed printing to stdout in ``CheetahWrapper``.
 
+Code style:
+
+  - Fixed a ``F811`` warning from ``flake8``:
+    redefinition of unused 'join' in ``ImportManager.py``.
+
 CI:
 
    - CI(GHActions): Install all Python and PyPy versions from ``conda-forge``.