diff --git a/src/impl_macros.rs b/src/impl_macros.rs
index 3da8c63..5772bae 100644
--- a/src/impl_macros.rs
+++ b/src/impl_macros.rs
@@ -2,7 +2,7 @@
 //! Implementation's internal macros
 
 macro_rules! debug_fmt_fields {
-    ($tyname:ident, $($($field:ident).+),*) => {
+    ($tyname:ident, $($($field:tt/*TODO ideally we would accept ident or tuple element here*/).+),*) => {
         fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
             f.debug_struct(stringify!($tyname))
                 $(