--- a/cc_bindings_from_rs/generate_bindings/generate_function.rs
+++ b/cc_bindings_from_rs/generate_bindings/generate_function.rs
@@ -819,2 +819,7 @@
         .map(|fully_qualified_name| fully_qualified_name.format_for_rs())
-        .expect("Generated trait method for a trait with an invalid rs name");
+        .ok_or_else(|| {
+            anyhow!(
+                "Failed to format trait name `{}`: trait does not have a canonical name",
+                db.tcx().def_path_str(trait_ref.def_id)
+            )
+        })?;