diff --git a/libyang/data.py b/libyang/data.py
index a8c0ed92..69649eba 100644
--- a/libyang/data.py
+++ b/libyang/data.py
@@ -552,6 +552,8 @@ def merge(
         if ret != lib.LY_SUCCESS:
             raise self.context.error("merge failed")
 
+        self.cdata = node_p[0]
+
     def iter_tree(self) -> Iterator["DNode"]:
         n = next_n = self.cdata
         while n != ffi.NULL: