#16154: fix some doctests in Doc/library.  Patch by Ravi Sinha.
diff --git a/Doc/library/math.rst b/Doc/library/math.rst
index 98c5b33..5d6f951 100644
--- a/Doc/library/math.rst
+++ b/Doc/library/math.rst
@@ -77,6 +77,8 @@
 
 
 .. function:: fsum(iterable)
+.. testsetup::
+        >>> from math import fsum
 
    Return an accurate floating point sum of values in the iterable.  Avoids
    loss of precision by tracking multiple intermediate partial sums::