--- black-25.1.0/tox.ini.orig
+++ black-25.1.0/tox.ini
@@ -4,7 +4,6 @@
 
 [testenv]
 setenv =
-    PYTHONPATH = {toxinidir}/src
     PYTHONWARNDEFAULTENCODING = 1
 skip_install = True
 # We use `recreate=True` because otherwise, on the second run of `tox -e py`,