diff --git a/include/mata/nft/nft.hh b/include/mata/nft/nft.hh
index 68c052a8..69cf1880 100644
--- a/include/mata/nft/nft.hh
+++ b/include/mata/nft/nft.hh
@@ -53,9 +53,9 @@ public:
     Levels(std::vector<Level>&& levels): super(std::move(levels)) {}
 
     /**
-     * @brief Append post vector to the delta.
+     * @brief Append @p levels_vector to the end of @c this.
      *
-     * @param post_vector Vector of posts to be appended.
+     * @param[in] levels_vector Vector of levels to be appended.
      */
     void append(const Levels& levels_vector) { for (const Level& level: levels_vector) { push_back(level); } }
 };