diff --git a/advlabdb/adminModelViews.py b/advlabdb/adminModelViews.py
index 7eaef29..0f8e850 100644
--- a/advlabdb/adminModelViews.py
+++ b/advlabdb/adminModelViews.py
@@ -348,7 +348,7 @@ class SemesterView(SecureAdminModelView):
     ]
 
     def customCreateModel(self, form):
-        return Semester.customInitFromOldSemester(
+        return Semester.initFromOldSemester(
             label=form.label.data,
             year=form.year.data,
             oldSemester=userActiveSemester(),
diff --git a/advlabdb/database_import.py b/advlabdb/database_import.py
index 02d8ed1..fd10ac4 100644
--- a/advlabdb/database_import.py
+++ b/advlabdb/database_import.py
@@ -202,7 +202,7 @@ def importFromFile(filePath):
 
         for i, studentNumber in enumerate(partStudents["student_number"]):
             studentNumber = int(studentNumber)
-            dbPartStudent = PartStudent.customInit(
+            dbPartStudent = PartStudent(
                 student=dbStudents[studentNumber],
                 part=dbParts[int(partStudents["part_id"][i])],
                 group=dbGroups[int(partStudents["group_id"][i])],
diff --git a/advlabdb/models.py b/advlabdb/models.py
index b4f5716..ec4dfa2 100644
--- a/advlabdb/models.py
+++ b/advlabdb/models.py
@@ -74,15 +74,15 @@ class PartStudent(db.Model):
     )
 
     def check(group, part):
-        if group and group.program != part.program:
+        if group is not None and group.program != part.program:
             raise DataBaseException(
                 f"Group's program {group.program} and student part's program {part.program} do not match!"
             )
 
-    def customInit(student, part, group=None):
-        PartStudent.check(group, part)
+    def __init__(self, *args, **kwargs):
+        PartStudent.check(kwargs.get("group"), kwargs["part"])
 
-        return PartStudent(student=student, part=part, group=group)
+        super().__init__(*args, **kwargs)
 
     def customUpdate(self, group, final_part_mark):
         Part.check(group, self.part)
@@ -442,7 +442,7 @@ class Semester(db.Model):
 
     __table_args__ = (db.UniqueConstraint(label, year),)
 
-    def customInitFromOldSemester(label, year, oldSemester, transferParts, transferAssistants):
+    def initFromOldSemester(label, year, oldSemester, transferParts, transferAssistants):
         semester = Semester(label=label, year=year)
 
         if transferParts:
diff --git a/advlabdb/scripts/test/test_database.py b/advlabdb/scripts/test/test_database.py
index d33bd68..0af700e 100644
--- a/advlabdb/scripts/test/test_database.py
+++ b/advlabdb/scripts/test/test_database.py
@@ -49,9 +49,9 @@ def main():
             db.session.add(student2)
             db.session.add(student3)
 
-            ps1 = PartStudent.customInit(student=student1, part=part1)
-            ps2 = PartStudent.customInit(student=student2, part=part1)
-            ps3 = PartStudent.customInit(student=student3, part=part2)
+            ps1 = PartStudent(student=student1, part=part1)
+            ps2 = PartStudent(student=student2, part=part1)
+            ps3 = PartStudent(student=student3, part=part2)
 
             db.session.add(ps1)
             db.session.add(ps2)