diff --git a/server/openslides/assignments/migrations/0024_assignmentpoll_entitled_users_remove_duplicates.py b/server/openslides/assignments/migrations/0024_assignmentpoll_entitled_users_remove_duplicates.py
new file mode 100644
index 000000000..79ef5d5a6
--- /dev/null
+++ b/server/openslides/assignments/migrations/0024_assignmentpoll_entitled_users_remove_duplicates.py
@@ -0,0 +1,18 @@
+# Generated by jsangmeister on 2021-04-08 11:27
+
+from django.db import migrations
+
+from ...poll.migrations.poll_migration_helper import remove_entitled_users_duplicates
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("assignments", "0023_assignmentpoll_change_fields_2"),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            remove_entitled_users_duplicates("assignments", "AssignmentPoll")
+        ),
+    ]
diff --git a/server/openslides/motions/migrations/0043_motionpoll_entitled_users_remove_duplicates.py b/server/openslides/motions/migrations/0043_motionpoll_entitled_users_remove_duplicates.py
new file mode 100644
index 000000000..19d0a93a8
--- /dev/null
+++ b/server/openslides/motions/migrations/0043_motionpoll_entitled_users_remove_duplicates.py
@@ -0,0 +1,16 @@
+# Generated by jsangmeister on 2021-04-08 11:27
+
+from django.db import migrations
+
+from ...poll.migrations.poll_migration_helper import remove_entitled_users_duplicates
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("motions", "0042_motionpoll_change_fields_2"),
+    ]
+
+    operations = [
+        migrations.RunPython(remove_entitled_users_duplicates("motions", "MotionPoll")),
+    ]
diff --git a/server/openslides/poll/migrations/poll_migration_helper.py b/server/openslides/poll/migrations/poll_migration_helper.py
index 3e6478ad3..27b9414b3 100644
--- a/server/openslides/poll/migrations/poll_migration_helper.py
+++ b/server/openslides/poll/migrations/poll_migration_helper.py
@@ -34,3 +34,25 @@ def calculate_vote_fields(poll_model_collection, poll_model_name):
                 poll.save(skip_autoupdate=True)
 
     return _calculate_vote_fields
+
+
+def remove_entitled_users_duplicates(poll_model_collection, poll_model_name):
+    """
+    Takes all polls of the given model and removes any duplicate entries from
+    entitled_users_at_stop
+    """
+
+    def _remove_entitled_users_duplicates(apps, schema_editor):
+        PollModel = apps.get_model(poll_model_collection, poll_model_name)
+        for poll in PollModel.objects.all():
+            if poll.entitled_users_at_stop:
+                new_entitled_users = []
+                entitled_users_ids = set()
+                for entry in poll.entitled_users_at_stop:
+                    if entry["user_id"] not in entitled_users_ids:
+                        entitled_users_ids.add(entry["user_id"])
+                        new_entitled_users.append(entry)
+                poll.entitled_users_at_stop = new_entitled_users
+                poll.save(skip_autoupdate=True)
+
+    return _remove_entitled_users_duplicates
diff --git a/server/openslides/poll/models.py b/server/openslides/poll/models.py
index d18ff0e12..a72e43617 100644
--- a/server/openslides/poll/models.py
+++ b/server/openslides/poll/models.py
@@ -275,9 +275,11 @@ class BasePoll(models.Model):
 
     def calculate_entitled_users(self):
         entitled_users = []
+        entitled_users_ids = set()
         for group in self.groups.all():
             for user in group.user_set.all():
-                if user.is_present:
+                if user.is_present and user.id not in entitled_users_ids:
+                    entitled_users_ids.add(user.id)
                     entitled_users.append(
                         {
                             "user_id": user.id,
diff --git a/server/tests/integration/motions/test_polls.py b/server/tests/integration/motions/test_polls.py
index 4743c72dd..730f9505e 100644
--- a/server/tests/integration/motions/test_polls.py
+++ b/server/tests/integration/motions/test_polls.py
@@ -1208,6 +1208,19 @@ class StopMotionPoll(TestCase):
             ],
         )
 
+    def test_stop_poll_assert_no_duplicate_entitled_users(self):
+        self.setup_entitled_users()
+        delegate_group = get_group_model().objects.get(pk=GROUP_DELEGATE_PK)
+        self.admin.groups.add(delegate_group)
+        self.poll.groups.add(delegate_group)
+
+        response = self.client.post(reverse("motionpoll-stop", args=[self.poll.pk]))
+        self.assertHttpStatusVerbose(response, status.HTTP_200_OK)
+        self.assertEqual(
+            MotionPoll.objects.get().entitled_users_at_stop,
+            [{"user_id": self.admin.id, "voted": False, "vote_delegated_to_id": None}],
+        )
+
 
 class PublishMotionPoll(TestCase):
     def advancedSetUp(self):