1 files changed, 4 insertions, 0 deletions
diff --git a/tox.ini b/tox.ini
index 509eb92..48d2aed 100644
--- a/tox.ini
+++ b/tox.ini
@@ -3,6 +3,10 @@ minversion = 3.1
 envlist = py27,py37,pep8
 basepython = python3
 ignore_basepython_conflict = True
+# Pin setuptools via virtualenv as latest virtualenv pulls in 65.3.0
+# version of setuptools for py37, which causes installation problems
+# (virtualenv 20.16.3 uses setuptools 63.4.1).
+requires = virtualenv<20.16.4
 
 [testenv]
 install_command = pip install {opts} {packages}