diff --git a/setup.py b/setup.py
index 043cd1fed4184d04566081f38c5f2df4e7451628..63b56f35327990cc83af8d642a1adb9af4ae0a1c 100644
--- a/setup.py
+++ b/setup.py
@@ -120,6 +120,9 @@ PACKAGE_DIRECTORIES = {
 INSTALL_REQUIRES = (
     'enum34>=1.0.4',
     'futures>=2.2.0',
+    # TODO(atash): eventually split the grpcio package into a metapackage
+    # depending on protobuf and the runtime component (independent of protobuf)
+    'protobuf>=3.0.0a3',
 )
 
 SETUP_REQUIRES = (