diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index dd4bcc9..05e81ba 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -24,6 +24,8 @@ jobs:
           python-version: '3.8'
       - run: pip install "tinycss2>=1.2.0"
       - run: python noshadows.py --tests
+        env:
+          PYTHONWARNINGS: error
 
   tracdjangoplugin:
     runs-on: ubuntu-20.04
@@ -39,6 +41,7 @@ jobs:
         run: python -m django test tracdjangoplugin.tests
         env:
           DJANGO_SETTINGS_MODULE: tracdjangoplugin.settings_tests
+          PYTHONWARNINGS: error
 
   traccheck:
     runs-on: ubuntu-20.04
@@ -53,6 +56,8 @@ jobs:
       - run: python traccheck.py lint trac-env/
         env:
           DJANGO_SETTINGS_MODULE: tracdjangoplugin.settings_tests
+          PYTHONWARNINGS: error
       - run: python traccheck.py components --check .TRACFREEZE.txt trac-env/
         env:
           DJANGO_SETTINGS_MODULE: tracdjangoplugin.settings_tests
+          PYTHONWARNINGS: error
diff --git a/DjangoPlugin/tracdjangoplugin/plugins.py b/DjangoPlugin/tracdjangoplugin/plugins.py
index 4e71f56..17bdab4 100644
--- a/DjangoPlugin/tracdjangoplugin/plugins.py
+++ b/DjangoPlugin/tracdjangoplugin/plugins.py
@@ -11,7 +11,8 @@
 
 from django.conf import settings
 from django.contrib.auth.forms import AuthenticationForm
-from django.utils.http import is_safe_url
+from django.utils.encoding import iri_to_uri
+from django.utils.http import url_has_allowed_host_and_scheme
 
 
 class CustomTheme(Component):
@@ -135,11 +136,14 @@ def do_post(self, req):
 
     def _get_safe_redirect_url(self, req):
         host = urlparse(req.base_url).hostname
-        redirect_url = req.args.get("next", "") or settings.LOGIN_REDIRECT_URL
-        if is_safe_url(redirect_url, allowed_hosts=[host]):
-            return redirect_url
-        else:
-            return settings.LOGIN_REDIRECT_URL
+        redirect_url = iri_to_uri(req.args.get("next", ""))
+
+        if not redirect_url:
+            redirect_url = settings.LOGIN_REDIRECT_URL
+        elif not url_has_allowed_host_and_scheme(redirect_url, allowed_hosts=[host]):
+            redirect_url = settings.LOGIN_REDIRECT_URL
+
+        return redirect_url
 
 
 class ReservedUsernamesComponent(Component):
diff --git a/DjangoPlugin/tracdjangoplugin/tests.py b/DjangoPlugin/tracdjangoplugin/tests.py
index 67befc3..828d089 100644
--- a/DjangoPlugin/tracdjangoplugin/tests.py
+++ b/DjangoPlugin/tracdjangoplugin/tests.py
@@ -85,13 +85,27 @@ def test_login_valid_with_custom_redirection_with_hostname(self):
     def test_login_valid_with_malicious_redirection(self):
         self.env.config.set("trac", "base_url", "http://localhost")
         User.objects.create_user(username="test", password="test")
-        with self.settings(LOGIN_REDIRECT_URL="/test"):
-            self.assertLoginSucceeds(
-                username="test",
-                password="test",
-                check_redirect="http://localhost/test",
-                extra_data={"next": "http://example.com/evil"},
-            )
+
+        # adapted from django/tests/auth_tests/test_views.py
+        for redirect_url in [
+            "http://example.com",
+            "http://example.com/evil",
+            "http:///example.com",
+            "https://example.com",
+            "ftp://example.com",
+            "///example.com",
+            "//example.com",
+            'javascript:alert("XSS")',
+        ]:
+            with self.subTest(url=redirect_url), self.settings(
+                LOGIN_REDIRECT_URL="/test"
+            ):
+                self.assertLoginSucceeds(
+                    username="test",
+                    password="test",
+                    check_redirect="http://localhost/test",
+                    extra_data={"next": redirect_url},
+                )
 
     def assertLoginFails(self, username, password, error_message=None):
         if error_message is None:
diff --git a/requirements.txt b/requirements.txt
index 6125e3a..a23f914 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 # spam-filter doesn't work without babel (but somehow doesn't list it in its requirements)
 Trac[pygments, babel]==1.6.0
 psycopg2==2.9.9 --no-binary=psycopg2
-Django==1.11.29
+Django==3.2.24
 libsass==0.23.0
 
 # Trac plugins