diff --git a/doc/ext/doctest.rst b/doc/ext/doctest.rst
index 95336df8b..47331dea2 100644
--- a/doc/ext/doctest.rst
+++ b/doc/ext/doctest.rst
@@ -79,7 +79,7 @@ a comma-separated list of group names.
 
          .. doctest::
             :pyversion: > 3.3
- 
+
      The supported operands are ``<``, ``<=``, ``==``, ``>=``, ``>``, and
      comparison is performed by `distutils.version.LooseVersion
      <https://www.python.org/dev/peps/pep-0386/#distutils>`__.