diff --git a/src/Conn.h b/src/Conn.h
index 9f42341d08..8534e3dd73 100644
--- a/src/Conn.h
+++ b/src/Conn.h
@@ -148,7 +148,8 @@ public:
     /**
      * Append additional entries to the history field in the connection record.
      */
-    void AppendAddl(const char* str);
+    [[deprecated("Remove in v7.1 - Appears unused and named rough. Use CheckHistory() or AddHistory() instead.")]] void
+    AppendAddl(const char* str);
 
     void Match(detail::Rule::PatternType type, const u_char* data, int len, bool is_orig, bool bol, bool eol,
                bool clear_state);