diff --git a/commcare_connect/opportunity/migrations/0063_alter_completedwork_unique_together.py b/commcare_connect/opportunity/migrations/0063_alter_completedwork_unique_together.py
new file mode 100644
index 00000000..d0359b31
--- /dev/null
+++ b/commcare_connect/opportunity/migrations/0063_alter_completedwork_unique_together.py
@@ -0,0 +1,16 @@
+# Generated by Django 4.2.5 on 2024-12-16 13:02
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("opportunity", "0062_opportunityaccess_invited_date"),
+    ]
+
+    operations = [
+        migrations.AlterUniqueTogether(
+            name="completedwork",
+            unique_together={("entity_id", "payment_unit")},
+        ),
+    ]
diff --git a/commcare_connect/opportunity/models.py b/commcare_connect/opportunity/models.py
index 6214d3fc..979f80fb 100644
--- a/commcare_connect/opportunity/models.py
+++ b/commcare_connect/opportunity/models.py
@@ -452,6 +452,9 @@ class CompletedWork(models.Model):
     status_modified_date = models.DateTimeField(null=True)
     payment_date = models.DateTimeField(null=True)
 
+    class Meta:
+        unique_together = ("entity_id", "payment_unit")
+
     def __init__(self, *args, **kwargs):
         self.status = CompletedWorkStatus.incomplete
         self.status_modified_date = now()