diff --git a/CHANGES.txt b/CHANGES.txt
index 4e43380..49a56b1 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,7 @@
+2.5.1
+====================
+* Add another Django 5.2 fix
+
 2.5.0 (2025-12-08)
 ====================
 * Adds compatibility with Django 5.2
diff --git a/courseaffils/lib.py b/courseaffils/lib.py
index fdbeb52..9fb5646 100644
--- a/courseaffils/lib.py
+++ b/courseaffils/lib.py
@@ -47,7 +47,7 @@ def in_course_or_404(username, group_or_course):
         raise Http404(response_body)
 
 
-ANONYMIZE_KEY = 'ccnmtl.courseaffils.anonymize'
+ANONYMIZE_KEY = 'ctl.courseaffils.anonymize'
 
 
 def handle_public_name(user, request):
diff --git a/courseaffils/middleware.py b/courseaffils/middleware.py
index b349970..84206ca 100644
--- a/courseaffils/middleware.py
+++ b/courseaffils/middleware.py
@@ -24,7 +24,7 @@
 except ImportError:
     pass
 
-SESSION_KEY = 'ccnmtl.courseaffils.course'
+SESSION_KEY = 'ctl.courseaffils.course'
 
 
 def has_anonymous_path(current_path):
@@ -178,7 +178,7 @@ def process_request(self, request, override_view=None):
 
         if chosen_course and \
            (chosen_course in available_courses or request.user.is_staff):
-            request.session[SESSION_KEY] = chosen_course
+            request.session[SESSION_KEY] = chosen_course.pk
             self.decorate_request(request, chosen_course)
             return None
 
diff --git a/courseaffils/tests/test_middleware.py b/courseaffils/tests/test_middleware.py
index f8a068c..64614fb 100644
--- a/courseaffils/tests/test_middleware.py
+++ b/courseaffils/tests/test_middleware.py
@@ -9,24 +9,30 @@
 from django.test import TestCase
 
 
-class StubRequest(object):
-    COOKIES = dict()
-    GET = dict()
-    POST = dict()
-    environ = dict()
-
-    def __init__(self, c):
-        self.path = "/foo/bar"
+class StubRequest:
+    def __init__(self, c=None, path='/foo/bar', method='GET'):
+        self.path = path
+        self.method = method
+        self.COOKIES = {}
+        self.GET = {}
+        self.POST = {}
+        self.environ = {}
+        self.session = {}
+
         if c:
-            self.session = {'ccnmtl.courseaffils.course': c}
-        else:
-            self.session = dict()
+            if hasattr(c, 'pk'):
+                self.session = {'ctl.courseaffils.course': c.pk}
+            else:
+                self.session = {'ctl.courseaffils.course': c}
 
     def get_full_path(self):
         return self.path
 
+    def is_secure(self):
+        return False
+
 
-class StubResponse(object):
+class StubResponse:
     content = ""
 
 
@@ -62,12 +68,12 @@ def test_is_anonymous_path(self):
         assert is_anonymous_path("/static/")
 
     def test_already_selected_course(self):
-        assert already_selected_course(StubRequest(True))
-        assert not already_selected_course(StubRequest(False))
+        assert already_selected_course(StubRequest(1))
+        assert not already_selected_course(StubRequest(0))
 
     def test_cmm_process_response(self):
         c = CourseManagerMiddleware(self)
-        assert c.process_response(StubRequest(True), "foo") == "foo"
+        assert c.process_response(StubRequest(1), "foo") == "foo"
 
     def test_cmm_process_response_anon(self):
         c = CourseManagerMiddleware(self)
diff --git a/courseaffils/views.py b/courseaffils/views.py
index b8d8d50..32fe433 100644
--- a/courseaffils/views.py
+++ b/courseaffils/views.py
@@ -18,7 +18,7 @@
     from django.utils.http import urlquote as quote
 
 
-SESSION_KEY = 'ccnmtl.courseaffils.course'
+SESSION_KEY = 'ctl.courseaffils.course'
 
 
 def get_courses_for_user(user):