diff --git a/nikola/nikola.py b/nikola/nikola.py
index 38dda09f9..5743255e8 100644
--- a/nikola/nikola.py
+++ b/nikola/nikola.py
@@ -27,6 +27,7 @@
 """The main Nikola site object."""
 
 import datetime
+from datetime import timezone
 import io
 import json
 import functools
@@ -1777,7 +1778,7 @@ def generic_rss_feed(self, lang, title, link, description, timeline,
             title=title,
             link=utils.encodelink(link),
             description=description,
-            lastBuildDate=datetime.datetime.utcnow(),
+            lastBuildDate=datetime.datetime.now(timezone.utc).replace(tzinfo=None),
             generator='Nikola (getnikola.com)',
             language=lang
         )
diff --git a/nikola/plugins/command/deploy.py b/nikola/plugins/command/deploy.py
index 9a47437d2..24b81e91a 100644
--- a/nikola/plugins/command/deploy.py
+++ b/nikola/plugins/command/deploy.py
@@ -28,7 +28,7 @@
 
 import subprocess
 import time
-from datetime import datetime
+from datetime import datetime, timezone
 
 import dateutil
 from blinker import signal
@@ -97,7 +97,7 @@ def _execute(self, command, args):
 
         self.logger.info("Successful deployment")
 
-        new_deploy = datetime.utcnow()
+        new_deploy = datetime.now(timezone.utc).replace(tzinfo=None)
         if last_deploy is None:
             last_deploy = new_deploy
         self._emit_deploy_event(last_deploy, new_deploy, clean, undeployed_posts)
diff --git a/nikola/plugins/compile/rest/listing.py b/nikola/plugins/compile/rest/listing.py
index f358f281f..7e996d468 100644
--- a/nikola/plugins/compile/rest/listing.py
+++ b/nikola/plugins/compile/rest/listing.py
@@ -37,13 +37,19 @@
 import docutils.parsers.rst.directives.misc
 import pygments
 import pygments.util
+import docutils
 from docutils import core
 from docutils import nodes
 from docutils.parsers.rst import Directive, directives
-from docutils.parsers.rst.roles import set_classes
 from docutils.parsers.rst.directives.misc import Include
 from pygments.lexers import get_lexer_by_name
 
+# Compatibility layer for docutils versions
+if docutils.__version_info__[:2] >= (0, 22):
+    from docutils.parsers.rst.roles import normalize_options
+else:
+    from docutils.parsers.rst.roles import set_classes as normalize_options
+
 from nikola import utils
 from nikola.plugin_categories import RestExtension
 
@@ -74,7 +80,7 @@ def run(self):
             language = self.arguments[0]
         else:
             language = 'text'
-        set_classes(self.options)
+        normalize_options(self.options)
         classes = ['code']
         if language:
             classes.append(language)
diff --git a/nikola/plugins/task/galleries.py b/nikola/plugins/task/galleries.py
index bb4a45851..d01fd43f6 100644
--- a/nikola/plugins/task/galleries.py
+++ b/nikola/plugins/task/galleries.py
@@ -27,6 +27,7 @@
 """Render image galleries."""
 
 import datetime
+from datetime import timezone
 import glob
 import io
 import json
@@ -763,7 +764,7 @@ def forward_slashes(path):
             title=title,
             link=make_url(permalink),
             description='',
-            lastBuildDate=datetime.datetime.utcnow(),
+            lastBuildDate=datetime.datetime.now(timezone.utc).replace(tzinfo=None),
             items=items,
             generator='https://getnikola.com/',
             language=lang
diff --git a/tests/integration/test_translated_content.py b/tests/integration/test_translated_content.py
index 9d1338f96..07fc5b17b 100644
--- a/tests/integration/test_translated_content.py
+++ b/tests/integration/test_translated_content.py
@@ -36,11 +36,11 @@ def test_translated_titles(build, output_dir, other_locale):
     # And now let's check the titles
     with io.open(normal_file, "r", encoding="utf8") as inf:
         doc = lxml.html.parse(inf)
-        assert doc.find("//title").text == "Foo | Demo Site"
+        assert doc.find(".//title").text == "Foo | Demo Site"
 
     with io.open(translated_file, "r", encoding="utf8") as inf:
         doc = lxml.html.parse(inf)
-        assert doc.find("//title").text == "Bar | Demo Site"
+        assert doc.find(".//title").text == "Bar | Demo Site"
 
 
 @pytest.fixture(scope="module")
diff --git a/tests/test_shortcodes.py b/tests/test_shortcodes.py
index 90409ad6f..c0ab88bc2 100644
--- a/tests/test_shortcodes.py
+++ b/tests/test_shortcodes.py
@@ -183,7 +183,7 @@ def __init__(self):
     def register_shortcode(self, name, f):
         """Register function f to handle shortcode "name"."""
         if name in self.shortcode_registry:
-            nikola.utils.LOGGER.warn("Shortcode name conflict: %s", name)
+            nikola.utils.LOGGER.warning("Shortcode name conflict: %s", name)
             return
         self.shortcode_registry[name] = f