diff --git a/manual/custom.py b/manual/custom.py
index b35ff29234..9b7f7e3490 100644
--- a/manual/custom.py
+++ b/manual/custom.py
@@ -355,8 +355,24 @@ def setup_man_pages(app):
     app.config['man_pages'] = man_pages
 
 
+def monkey_patch_docutils():
+    # fixes a bug in sphinx https://github.com/sphinx-doc/sphinx/issues/5150
+    from docutils import nodes
+
+    orig_method = nodes.document.set_duplicate_name_id
+
+    def set_duplicate_name_id(*a):
+        try:
+            return orig_method(*a)
+        except KeyError:
+            pass
+
+    nodes.document.set_duplicate_name_id = set_duplicate_name_id
+
+
 def setup(app):
     from docutils.parsers.rst import roles
+    monkey_patch_docutils()
     setup_man_pages(app)
     app.add_builder(EPUBHelpBuilder)
     app.add_builder(LaTeXHelpBuilder)
diff --git a/manual/epub.py b/manual/epub.py
index dd93e34817..e3e36f91ad 100644
--- a/manual/epub.py
+++ b/manual/epub.py
@@ -21,8 +21,13 @@ from polyglot.builtins import iteritems
 class EPUBHelpBuilder(EpubBuilder):
     name = 'myepub'
 
-    def build_epub(self, outdir, outname):
-        EpubBuilder.build_epub(self, outdir, outname)
+    def build_epub(self, outdir=None, outname=None):
+        if outdir:
+            EpubBuilder.build_epub(self, outdir, outname)
+        else:
+            EpubBuilder.build_epub(self)
+            outdir = self.outdir
+            outname = self.config.epub_basename + '.epub'
         container = get_container(os.path.join(outdir, outname))
         self.fix_epub(container)
         container.commit()