diff --git a/advlabdb/adminModelViews.py b/advlabdb/adminModelViews.py
index 1553395..46fccd5 100644
--- a/advlabdb/adminModelViews.py
+++ b/advlabdb/adminModelViews.py
@@ -1194,7 +1194,7 @@ class AppointmentView(SecureAdminModelView):
 class ExperimentMarkView(SecureAdminModelView):
     class StudentFilter(FilterEqual):
         def validate(self, value):
-            if Student.query.get(value):
+            if db.session.get(Student, value) is not None:
                 return True
             else:
                 return False
diff --git a/advlabdb/dependent_funs.py b/advlabdb/dependent_funs.py
index 5826e6e..d4504f4 100644
--- a/advlabdb/dependent_funs.py
+++ b/advlabdb/dependent_funs.py
@@ -20,8 +20,8 @@ def userActiveSemester(flashWarning=False):
         current_user.active_semester_id = lastSemesterId
         db.session.commit()
     elif current_user.active_semester_id != lastSemesterId:
-        activeSemester = Semester.query.get(current_user.active_semester_id)
-        if activeSemester:
+        activeSemester = db.session.get(Semester, current_user.active_semester_id)
+        if activeSemester is not None:
             if flashWarning:
                 flash(f"You are in the old semester {activeSemester.repr()}!", "warning")
         else:
@@ -29,13 +29,13 @@ def userActiveSemester(flashWarning=False):
             db.session.commit()
             flash("Semester changed!", "warning")
 
-    return Semester.query.get(current_user.active_semester_id)
+    return db.session.get(Semester, current_user.active_semester_id)
 
 
 def setUserActiveSemester(semesterId):
     if current_user.active_semester_id != semesterId:
-        semester = Semester.query.get(semesterId)
-        if semester:
+        semester = db.session.get(Semester, semesterId)
+        if semester is not None:
             try:
                 current_user.active_semester_id = semesterId
                 db.session.commit()