diff --git a/InvenTree/order/migrations/0052_auto_20211014_0631.py b/InvenTree/order/migrations/0052_auto_20211014_0631.py
new file mode 100644
index 0000000000..93d3f86038
--- /dev/null
+++ b/InvenTree/order/migrations/0052_auto_20211014_0631.py
@@ -0,0 +1,80 @@
+# Generated by Django 3.2.5 on 2021-10-14 06:31
+
+import re
+
+from django.db import migrations
+
+def build_refs(apps, schema_editor):
+    """
+    Rebuild the integer "reference fields" for existing Build objects
+    """
+
+    print("\n - Rebuilding reference field for PurchaseOrder model...")
+
+    PurchaseOrder = apps.get_model('order', 'purchaseorder')
+
+    n = PurchaseOrder.objects.count()
+
+    for order in PurchaseOrder.objects.all():
+
+        ref = 0
+
+        result = re.match(r"^(\d+)", order.reference)
+
+        if result and len(result.groups()) == 1:
+            try:
+                ref = int(result.groups()[0])
+            except:
+                ref = 0
+
+        order.reference_int = ref
+        order.save()
+
+    print(f" - Updated {n} PurchaseOrder objects")
+
+    print("\n - Rebuilding reference field for SalesOrder model...")
+
+    SalesOrder = apps.get_model('order', 'salesorder')
+
+    n = SalesOrder.objects.count()
+
+    for order in SalesOrder.objects.all():
+
+        ref = 0
+
+        result = re.match(r"^(\d+)", order.reference)
+
+        if result and len(result.groups()) == 1:
+            try:
+                ref = int(result.groups()[0])
+            except:
+                ref = 0
+
+        order.reference_int = ref
+        order.save()
+
+    print(f" - Updated {n} SalesOrder objects")
+
+    print(f" - COMPLETE! -")
+
+
+def unbuild_refs(apps, schema_editor):
+    """
+    Provided only for reverse migration compatibility
+    """
+    pass
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('order', '0051_auto_20211014_0623'),
+    ]
+
+
+    operations = [
+        migrations.RunPython(
+            build_refs,
+            reverse_code=unbuild_refs
+        )
+    ]