1 files changed, 3 insertions, 0 deletions
diff --git a/tox.ini b/tox.ini
index 76a1b1db..d1b89374 100644
--- a/tox.ini
+++ b/tox.ini
@@ -31,6 +31,9 @@ setenv =
     pypy,pypy3: COVERAGE_NO_CTRACER=no C extension under PyPy
     jython: COVERAGE_NO_CTRACER=no C extension under Jython
     jython: PYTEST_ADDOPTS=-n 0
+    # For some tests, we need .pyc files written in the current directory,
+    # so override any local setting.
+    PYTHONPYCACHEPREFIX=
 
 commands =
     python setup.py --quiet clean develop