diff --git a/crates/xml/derive/src/xml_struct/impl_se.rs b/crates/xml/derive/src/xml_struct/impl_se.rs
index ec5c651..bff0a65 100644
--- a/crates/xml/derive/src/xml_struct/impl_se.rs
+++ b/crates/xml/derive/src/xml_struct/impl_se.rs
@@ -70,13 +70,12 @@ impl NamedStruct {
                 .ns_prefix
                 .iter()
                 .map(|(ns, prefix)| {
-                    let sep = if !prefix.value().is_empty() {
-                        b":".to_vec()
+                    let attr_name = if prefix.value().is_empty() {
+                        "xmlns".to_owned()
                     } else {
-                        b"".to_vec()
+                        format!("xmlns:{}", prefix.value())
                     };
-                    let attr_name = [b"xmlns".as_ref(), &sep, prefix.value().as_bytes()].concat();
-                    let a = syn::LitByteStr::new(&attr_name, prefix.span());
+                    let a = syn::LitByteStr::new(attr_name.as_bytes(), prefix.span());
                     quote! {
                          bytes_start.push_attribute((#a.as_ref(), #ns.as_ref()));
                     }