diff --git a/tox.ini b/tox.ini
index 5a8d9f209..b2d1033fe 100644
--- a/tox.ini
+++ b/tox.ini
@@ -6,6 +6,11 @@ skip_missing_interpreters=true
 [testenv]
 setenv =
     cy: FONTTOOLS_WITH_CYTHON=1
+# use 'download = true' to have tox install the latest pip inside the virtualenv.
+# We need this to be able to install skia-pathops on Linux, which uses a
+# relatively recent 'manylinux2014' platform tag.
+# https://github.com/tox-dev/tox/issues/791#issuecomment-518713438
+download = true
 deps =
     cov: coverage>=4.3
     pytest