#15438: merge with 3.2.
diff --git a/Doc/library/math.rst b/Doc/library/math.rst
index 2f2558b..b69d6c6 100644
--- a/Doc/library/math.rst
+++ b/Doc/library/math.rst
@@ -215,6 +215,10 @@
    ``x`` is negative, and ``y`` is not an integer then ``pow(x, y)``
    is undefined, and raises :exc:`ValueError`.
 
+   Unlike the built-in ``**`` operator, :func:`math.pow` converts both
+   its arguments to type :class:`float`.  Use ``**`` or the built-in
+   :func:`pow` function for computing exact integer powers.
+
 
 .. function:: sqrt(x)