diff --git a/doc/python/sankey-diagram.md b/doc/python/sankey-diagram.md
index 5ce928345eb..f91a28982bb 100644
--- a/doc/python/sankey-diagram.md
+++ b/doc/python/sankey-diagram.md
@@ -53,7 +53,7 @@ fig = go.Figure(data=[go.Sankey(
       color = "blue"
     ),
     link = dict(
-      source = [0, 1, 0, 2, 3, 3], # indices correspond to labels, eg A1, A2, A2, B1, ...
+      source = [0, 1, 0, 2, 3, 3], # indices correspond to labels, eg A1, A2, A1, B1, ...
       target = [2, 3, 3, 4, 4, 5],
       value = [8, 4, 2, 8, 4, 2]
   ))])