diff --git a/stubs/s2clientprotocol/METADATA.toml b/stubs/s2clientprotocol/METADATA.toml
new file mode 100644
index 000000000000..ec031f311df8
--- /dev/null
+++ b/stubs/s2clientprotocol/METADATA.toml
@@ -0,0 +1,2 @@
+version = "5.*"
+requires = ["protobuf<4", "types-protobuf"]