diff --git a/python/requirements-optional.txt b/python/requirements-optional.txt
index 63bf68191f..5e6a183706 100644
--- a/python/requirements-optional.txt
+++ b/python/requirements-optional.txt
@@ -1,3 +1,4 @@
 hidapi >= 0.7.99.post20
 rlp >= 1.1.0
 web3 >= 4.8
+Pillow