diff --git a/pkgs/applications/science/math/sage/patches/docutils-0.15.patch b/pkgs/applications/science/math/sage/patches/docutils-0.15.patch
new file mode 100644
index 00000000000..63f5d2e146d
--- /dev/null
+++ b/pkgs/applications/science/math/sage/patches/docutils-0.15.patch
@@ -0,0 +1,24 @@
+diff --git a/src/sage/misc/sphinxify.py b/src/sage/misc/sphinxify.py
+index 4849c2bffa..76b7bc8602 100644
+--- a/src/sage/misc/sphinxify.py
++++ b/src/sage/misc/sphinxify.py
+@@ -25,6 +25,7 @@ from __future__ import absolute_import, print_function
+ import os
+ import re
+ import shutil
++import warnings
+ from tempfile import mkdtemp
+ from sphinx.application import Sphinx
+ 
+@@ -120,7 +121,10 @@ smart_quotes = no""")
+     # buildername, confoverrides, status, warning, freshenv).
+     sphinx_app = Sphinx(srcdir, confdir, outdir, doctreedir, format,
+                         confoverrides, None, None, True)
+-    sphinx_app.build(None, [rst_name])
++    with warnings.catch_warnings():
++        # Quick and dirty workaround for https://trac.sagemath.org/ticket/28856#comment:19
++        warnings.simplefilter("ignore")
++        sphinx_app.build(None, [rst_name])
+     sys.path = old_sys_path
+ 
+     # We need to remove "_" from __builtin__ that the gettext module installs
diff --git a/pkgs/applications/science/math/sage/sage-src.nix b/pkgs/applications/science/math/sage/sage-src.nix
index 4530cbf69f4..1cbea74edae 100644
--- a/pkgs/applications/science/math/sage/sage-src.nix
+++ b/pkgs/applications/science/math/sage/sage-src.nix
@@ -52,6 +52,11 @@ stdenv.mkDerivation rec {
     # Parallelize docubuild using subprocesses, fixing an isolation issue. See
     # https://groups.google.com/forum/#!topic/sage-packaging/YGOm8tkADrE
     ./patches/sphinx-docbuild-subprocesses.patch
+
+    # Fix doctest failures with docutils 0.15:
+    # https://nix-cache.s3.amazonaws.com/log/dzmzrb2zvardsmpy7idg7djkizmkzdhs-sage-tests-8.9.drv
+    # https://trac.sagemath.org/ticket/28856#comment:19
+    ./patches/docutils-0.15.patch
   ];
 
   # Since sage unfortunately does not release bugfix releases, packagers must