diff --git a/pyproject.toml b/pyproject.toml
index bce1708f..fb7c6109 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -16,7 +16,7 @@ colorlog = "4.0.2"
 sawtooth-sdk = "1.1.3"
 sawtooth-signing = "1.1.3"
 cryptography = "2.5"
-protobuf = "3.6.1"
+protobuf = "3.9.1"
 requests = "2.21.0"
 pyOpenSSL = "18.0.0"
 aiohttp = "3.4.4"