diff --git a/inginious/frontend/flask/mongo_sessions.py b/inginious/frontend/flask/mongo_sessions.py
index b6cffdc89..937017976 100644
--- a/inginious/frontend/flask/mongo_sessions.py
+++ b/inginious/frontend/flask/mongo_sessions.py
@@ -98,7 +98,7 @@ def open_session(self, app, request):
 
         store_id = sid
         document = self.store.find_one({'_id': store_id})
-        if document and document.get('expiration') <= datetime.now(timezone.utc):
+        if document and document['expiration'].replace(tzinfo=timezone.utc) <= datetime.now(timezone.utc):
             # Delete expired session
             self.store.delete_one({'_id': store_id})
             document = None
diff --git a/inginious/frontend/lti_grade_manager.py b/inginious/frontend/lti_grade_manager.py
index 7ab2886a3..8f3eb39c5 100644
--- a/inginious/frontend/lti_grade_manager.py
+++ b/inginious/frontend/lti_grade_manager.py
@@ -73,7 +73,6 @@ def run(self):
                 try:
                     course = self._app.course_factory.get_course(courseid)
                     task = course.get_task(taskid)
-                    print(self._app.user_manager.get_task_cache(username, courseid, task.get_id()))
                     grade = self._app.user_manager.get_task_cache(username, courseid, task.get_id())["grade"]
                 except Exception:
                     self._logger.error("An exception occurred while getting a course/LTI secret/grade in LTIGradeManager.", exc_info=True)
diff --git a/inginious/frontend/pages/lti.py b/inginious/frontend/pages/lti.py
index 066c4fed0..7b7019851 100644
--- a/inginious/frontend/pages/lti.py
+++ b/inginious/frontend/pages/lti.py
@@ -70,7 +70,7 @@ def GET_AUTH(self):
         return self.template_helper.render("lti_bind.html", success=False, data=data, error="")
 
     def POST_AUTH(self):
-        data, error = self._get_lti_session_data_or_error()
+        data, error = self._get_lti_session_data()
         if error:
             return error
 
@@ -222,6 +222,7 @@ def _find_realname(self, launch_data):
         return launch_data["sub"]
 
 class LTILoginPage(INGIniousPage):
+    @property
     def is_lti_page(self):
         return True
 
diff --git a/inginious/frontend/submission_manager.py b/inginious/frontend/submission_manager.py
index 8f75d8cd0..156e8c1e3 100644
--- a/inginious/frontend/submission_manager.py
+++ b/inginious/frontend/submission_manager.py
@@ -97,7 +97,7 @@ def _job_done_callback(self, submissionid, course, task, result, grade, problems
 
         self._plugin_manager.call_hook("submission_done", submission=submission, archive=archive, newsub=newsub)
 
-        if course.lti_send_back_grade:
+        if course.lti_send_back_grade():
             for username in submission["username"]:
                 self._lti_grade_manager.add(username,
                                               submission["courseid"],
diff --git a/inginious/frontend/user_manager.py b/inginious/frontend/user_manager.py
index 1f45bf1ea..241353f03 100644
--- a/inginious/frontend/user_manager.py
+++ b/inginious/frontend/user_manager.py
@@ -118,7 +118,6 @@ def session_is_lti(self) -> bool:
     def _lti_session(self):
         """ Returns the LTI session dict. """
         assert self.session_is_lti()
-        print("get session", flask.request.args.get('session_id'), flask.g.get('lti_session_id'))
         if 'lti_session' not in flask.g:
             if 'session_id' in flask.request.args:
                 flask.g.lti_session = self._database.lti_sessions.find_one({'session_id': flask.request.args['session_id']})
@@ -129,7 +128,6 @@ def _lti_session(self):
     @staticmethod
     def _lti_session_save(app, response):
         """ Saves in database the LTI session. This function is a Flask event receiver. """
-        print("save session", flask.request.args.get('session_id'), flask.g.get('lti_session_id'))
         if app.user_manager.session_is_lti():
             lti_session_id = flask.request.args.get('session_id', flask.g.get('lti_session_id'))
             app.user_manager._database.lti_sessions.find_one_and_update({'session_id': lti_session_id}, {'$set': flask.g.lti_session}, upsert=True)
@@ -138,7 +136,6 @@ def _lti_session_save(app, response):
     @property
     def _session(self):
         """ Returns the session. """
-        print(self._flask_session, self._lti_session)
         return self._flask_session if not self.session_is_lti() else self._lti_session
 
     def session_logged_in(self):
diff --git a/setup.py b/setup.py
index 8ad382983..efd920189 100644
--- a/setup.py
+++ b/setup.py
@@ -15,7 +15,6 @@
     "Flask-Mail==0.9.1",
     "itsdangerous==2.1.2",
     "Jinja2==3.1.3",
-    "lti==0.9.5",
     "PyLTI1p3==2.0.0",
     "msgpack==1.0.7",
     "natsort==8.4.0",