diff --git a/py-polars/polars/expr/expr.py b/py-polars/polars/expr/expr.py
index e0487c6ee99c..9c856438623b 100644
--- a/py-polars/polars/expr/expr.py
+++ b/py-polars/polars/expr/expr.py
@@ -9263,7 +9263,7 @@ def replace(
             Accepts expression input. Sequences are parsed as Series,
             other non-expression inputs are parsed as literals.
             Also accepts a mapping of values to their replacement as syntactic sugar for
-            `replace(new=Series(mapping.keys()), old=Series(mapping.values()))`.
+            `replace(old=Series(mapping.keys()), new=Series(mapping.values()))`.
         new
             Value or sequence of values to replace by.
             Accepts expression input. Sequences are parsed as Series,
diff --git a/py-polars/polars/series/series.py b/py-polars/polars/series/series.py
index 6a1e9c4f127f..11a7dcf1d72c 100644
--- a/py-polars/polars/series/series.py
+++ b/py-polars/polars/series/series.py
@@ -6584,7 +6584,7 @@ def replace(
         old
             Value or sequence of values to replace.
             Also accepts a mapping of values to their replacement as syntactic sugar for
-            `replace(new=Series(mapping.keys()), old=Series(mapping.values()))`.
+            `replace(old=Series(mapping.keys()), new=Series(mapping.values()))`.
         new
             Value or sequence of values to replace by.
             Length must match the length of `old` or have length 1.