data FEATURE add lyd_first_sibling() function
diff --git a/src/tree_data.h b/src/tree_data.h
index 1a2fb46..a5accd5 100644
--- a/src/tree_data.h
+++ b/src/tree_data.h
@@ -786,6 +786,15 @@
 uint32_t lyd_list_pos(const struct lyd_node *instance);
 
 /**
+ * @brief Get the first sibling of the given node.
+ *
+ * @param[in] node Node which first sibling is going to be the result.
+ * @return The first sibling of the given node or the node itself if it is the first child of the parent.
+ */
+struct lyd_node *
+lyd_first_sibling(const struct lyd_node *node);
+
+/**
  * @brief Learn the length of LYB data.
  *
  * @param[in] data LYB data to examine.