diff --git a/protocol/src/protocol/forge.rs b/protocol/src/protocol/forge.rs
index 841df92..005a887 100644
--- a/protocol/src/protocol/forge.rs
+++ b/protocol/src/protocol/forge.rs
@@ -85,6 +85,9 @@ impl Serializable for ModIdMapping {
     }
 }
 
+pub static BLOCK_NAMESPACE: &'static str = "\u{1}";
+pub static ITEM_NAMESPACE: &'static str = "\u{2}";
+
 #[derive(Debug)]
 pub enum FmlHs {
     ServerHello {