diff --git a/tests/requirements/py3.txt b/tests/requirements/py3.txt
index ec80550858..cc84522ca0 100644
--- a/tests/requirements/py3.txt
+++ b/tests/requirements/py3.txt
@@ -4,7 +4,7 @@ docutils
 geoip2
 jinja2 >= 2.9.2
 numpy
-Pillow
+Pillow != 5.4.0
 # pylibmc/libmemcached can't be built on Windows.
 pylibmc; sys.platform != 'win32'
 python-memcached >= 1.59