--- a/xpcom/rust/nsstring/src/lib.rs
+++ b/xpcom/rust/nsstring/src/lib.rs
@@ -172,16 +172,17 @@ macro_rules! define_string_types {
         ///
         /// This type may also be used in place of a C++ ns[C]String inside of
         /// struct definitions which are shared with C++, as it has identical
         /// layout to our ns[C]String type.
         ///
         /// This struct will leak its data if dropped from rust. See the module
         /// documentation for more information on this type.
         #[repr(C)]
+        #[derive(Debug)]
         pub struct $StringRepr {
             data: *const $char_t,
             length: u32,
             flags: u32,
         }
 
         impl Deref for $StringRepr {
             type Target = $AString;