diff --git a/cylc/sphinx_ext/cylc_lang/autodocumenters.py b/cylc/sphinx_ext/cylc_lang/autodocumenters.py
index d26eda0..279797f 100644
--- a/cylc/sphinx_ext/cylc_lang/autodocumenters.py
+++ b/cylc/sphinx_ext/cylc_lang/autodocumenters.py
@@ -22,6 +22,7 @@ def get_vdr_info(vdr):
     except KeyError:
         return CylcConfigValidator.V_TYPE_HELP[vdr]
 
+
 def get_obj_from_module(namespace):
     """
         >>> get_obj_from_module('os')  # doctest: +ELLIPSIS
@@ -156,8 +157,6 @@ class CylcAutoDirective(Directive):
     required_arguments = 1
     optional_arguments = 1
 
-
-
     @staticmethod
     def doc_conf(name):
         return [
diff --git a/cylc/sphinx_ext/cylc_lang/domains.py b/cylc/sphinx_ext/cylc_lang/domains.py
index 07bb3d8..12356d5 100644
--- a/cylc/sphinx_ext/cylc_lang/domains.py
+++ b/cylc/sphinx_ext/cylc_lang/domains.py
@@ -372,7 +372,7 @@ def process_link(self, env, refnode, has_explicit_title, title, target):
             for context, _ in env.ref_context.items()
             if isinstance(context, tuple)
             and context[0] == 'cylc'
-        )) # TODO combine
+        ))  # TODO combine
         return title, target
 
 
diff --git a/setup.py b/setup.py
index 40c4c87..ee14c0e 100644
--- a/setup.py
+++ b/setup.py
@@ -70,6 +70,7 @@ def get_version(filename):
     long_description=open('README.rst', 'r').read(),
     install_requires=[
         'sphinx>=2.1.0',
+        # TODO: docutils version is pinned due to issue with hieroglyph
         'docutils<0.16.0'
     ],
     extras_require=REQS,