diff --git a/requirements.txt b/requirements.txt
index 3983067..2dada97 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,7 @@
 aiohttp
 click
 py4j
 psutil
+protobuf != 4.21.*  # https://github.com/protocolbuffers/protobuf/issues/10151
 grpcio-tools
 mypy-protobuf