diff --git a/scripts/construct/build_pb.py b/scripts/construct/build_pb.py
index 97721e0..166b764 100644
--- a/scripts/construct/build_pb.py
+++ b/scripts/construct/build_pb.py
@@ -85,14 +85,14 @@ parser.add_option(
     "",
     "--cpp_out",
     dest = "cpp_out",
-    default = True,
+    default = '',
     help = "",
 )
 parser.add_option(
     "",
     "--python_out",
     dest = "python_out",
-    default = True,
+    default = '',
     help = "",
 )
 parser.add_option(