Bump namespace to 04
diff --git a/syntax/mangle.rs b/syntax/mangle.rs
index c9392db..1c8c917 100644
--- a/syntax/mangle.rs
+++ b/syntax/mangle.rs
@@ -3,7 +3,7 @@
 use crate::syntax::ExternFn;
 use proc_macro2::Ident;
 
-const CXXBRIDGE: &str = "cxxbridge03";
+const CXXBRIDGE: &str = "cxxbridge04";
 
 macro_rules! join {
     ($($segment:expr),*) => {