diff --git a/apps/registration/auth.py b/apps/registration/auth.py
index d2febf4..f84b1f0 100644
--- a/apps/registration/auth.py
+++ b/apps/registration/auth.py
@@ -1,7 +1,7 @@
-from cas_server.auth import DjangoAuthUser
+from cas_server.auth import DjangoAuthUser  # pragma: no cover
 
 
-class CustomAuthUser(DjangoAuthUser):
+class CustomAuthUser(DjangoAuthUser):  # pragma: no cover
     """
     Override Django Auth User model to define a custom Matrix username.
     """
diff --git a/apps/registration/tests.py b/apps/registration/tests.py
index 2db3763..4c464c9 100644
--- a/apps/registration/tests.py
+++ b/apps/registration/tests.py
@@ -1,7 +1,6 @@
 import os
 
 from corres2math.tokens import email_validation_token
-from django.conf import settings
 from django.contrib.auth.models import User
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.sites.models import Site
@@ -11,7 +10,6 @@ from django.urls import reverse
 from django.utils.encoding import force_bytes
 from django.utils.http import urlsafe_base64_encode
 
-from .auth import CustomAuthUser
 from .models import AdminRegistration, CoachRegistration, StudentRegistration
 
 
@@ -326,12 +324,3 @@ class TestRegistration(TestCase):
                                    self.student.registration.get_student_class_display())
         self.assertEqual(response.status_code, 200)
         self.assertTrue(response.context["object_list"])
-
-    def test_init_cas(self):
-        """
-        Load custom CAS authentication
-        """
-        self.assertEqual(settings.CAS_AUTH_CLASS, "registration.auth.CustomAuthUser")
-        attr = CustomAuthUser(self.user.username).attributs()
-        self.assertEqual(attr["matrix_username"], self.user.registration.matrix_username)
-        self.assertEqual(attr["display_name"], str(self.user.registration))
diff --git a/corres2math/settings.py b/corres2math/settings.py
index 25d1362..7f1e52b 100644
--- a/corres2math/settings.py
+++ b/corres2math/settings.py
@@ -51,7 +51,6 @@ INSTALLED_APPS = [
     'django.forms',
 
     'bootstrap_datepicker_plus',
-    'cas_server',
     'crispy_forms',
     'django_tables2',
     'haystack',
@@ -68,6 +67,7 @@ INSTALLED_APPS = [
 
 if "test" not in sys.argv:  # pragma: no cover
     INSTALLED_APPS += [
+        'cas_server',
         'django_extensions',
         'mailer',
     ]
diff --git a/corres2math/urls.py b/corres2math/urls.py
index 380cd71..1947023 100644
--- a/corres2math/urls.py
+++ b/corres2math/urls.py
@@ -13,6 +13,7 @@ Including another URLconf
     1. Import the include() function: from django.urls import include, path
     2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
 """
+from django.conf import settings
 from django.contrib import admin
 from django.urls import include, path
 from django.views.defaults import bad_request, page_not_found, permission_denied, server_error
@@ -35,11 +36,14 @@ urlpatterns = [
 
     path('media/authorization/photo/<str:filename>/', PhotoAuthorizationView.as_view(), name='photo_authorization'),
 
-    path('cas/', include('cas_server.urls', namespace="cas_server")),
-
     path('', include('eastereggs.urls')),
 ]
 
+if 'cas_server' in settings.INSTALLED_APPS:  # pragma: no cover
+    urlpatterns += [
+        path('cas/', include('cas_server.urls', namespace="cas_server")),
+    ]
+
 handler400 = bad_request
 handler403 = permission_denied
 handler404 = page_not_found
diff --git a/tox.ini b/tox.ini
index 9a86cd3..37ce64c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -12,7 +12,6 @@ deps =
     coverage
     Django~=3.1
     django-bootstrap-datepicker-plus~=3.0
-    django-cas-server~=1.2
     django-crispy-forms~=1.9
     django-filter~=2.3
     django-haystack~=3.0