1 files changed, 2 insertions, 1 deletions
diff --git a/src/grammar.cc b/src/grammar.cc
index 6ed2766..c94a86f 100644
--- a/src/grammar.cc
+++ b/src/grammar.cc
@@ -224,7 +224,8 @@ class GrammarLoader {
         if (root_index.has_value()) {
           errors_.warn(first_pass_elements.find(second_pass_elements[i]->name)
                            ->second.loc,
-                       "Is not referenced but also not root");
+                       std::format("{} is not referenced but also not root",
+                                   second_pass_elements[i]->name));
         } else {
           root_index = i;
         }