diff --git a/grr/proto/setup.py b/grr/proto/setup.py
index d7db3d8e4..deaca15d8 100644
--- a/grr/proto/setup.py
+++ b/grr/proto/setup.py
@@ -17,7 +17,7 @@
 os.chdir(THIS_DIRECTORY)
 
 GRPCIO_TOOLS = "grpcio-tools==1.29.0"
-PROTOBUF = "protobuf==3.12.2"
+PROTOBUF = "protobuf>=3.12.2,<4"
 
 
 def get_config():