diff --git a/src/libotutil/ot-log-utils.h b/src/libotutil/ot-log-utils.h
index 5e0502ab..8d9786de 100644
--- a/src/libotutil/ot-log-utils.h
+++ b/src/libotutil/ot-log-utils.h
@@ -26,6 +26,6 @@ G_BEGIN_DECLS
 
 void ot_log_structured_print_id_v (const char *message_id,
                                    const char *format,
-                                   ...);
+                                   ...) G_GNUC_PRINTF(2, 3);
 
 G_END_DECLS