diff --git a/InvenTree/InvenTree/static/css/inventree.css b/InvenTree/InvenTree/static/css/inventree.css
index adb5a41ee6..592bef396a 100644
--- a/InvenTree/InvenTree/static/css/inventree.css
+++ b/InvenTree/InvenTree/static/css/inventree.css
@@ -1037,6 +1037,11 @@ a.anchor {
     height: 30px;
 }
 
+/* Force minimum width of number input fields to show at least ~5 digits */
+input[type='number']{
+    min-width: 80px;
+}
+
 .search-menu {
     padding-top: 2rem;
 }
diff --git a/InvenTree/order/migrations/0049_alter_purchaseorderlineitem_unique_together.py b/InvenTree/order/migrations/0049_alter_purchaseorderlineitem_unique_together.py
new file mode 100644
index 0000000000..c451e1754d
--- /dev/null
+++ b/InvenTree/order/migrations/0049_alter_purchaseorderlineitem_unique_together.py
@@ -0,0 +1,18 @@
+# Generated by Django 3.2.4 on 2021-08-12 17:49
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('company', '0040_alter_company_currency'),
+        ('order', '0048_auto_20210702_2321'),
+    ]
+
+    operations = [
+        migrations.AlterUniqueTogether(
+            name='purchaseorderlineitem',
+            unique_together={('order', 'part', 'quantity', 'purchase_price')},
+        ),
+    ]
diff --git a/InvenTree/order/models.py b/InvenTree/order/models.py
index 248ecb277d..e55f5203ba 100644
--- a/InvenTree/order/models.py
+++ b/InvenTree/order/models.py
@@ -729,7 +729,7 @@ class PurchaseOrderLineItem(OrderLineItem):
 
     class Meta:
         unique_together = (
-            ('order', 'part')
+            ('order', 'part', 'quantity', 'purchase_price')
         )
 
     def __str__(self):
diff --git a/InvenTree/order/templates/order/order_wizard/match_parts.html b/InvenTree/order/templates/order/order_wizard/match_parts.html
index e0f030bad5..4f84d205ee 100644
--- a/InvenTree/order/templates/order/order_wizard/match_parts.html
+++ b/InvenTree/order/templates/order/order_wizard/match_parts.html
@@ -115,7 +115,7 @@
 {{ block.super }}
 
 $('.bomselect').select2({
-    dropdownAutoWidth: true,
+    width: '100%',
     matcher: partialMatcher,
 });
 
diff --git a/InvenTree/order/templates/order/purchase_order_detail.html b/InvenTree/order/templates/order/purchase_order_detail.html
index b05bfa7cc2..ed352d1135 100644
--- a/InvenTree/order/templates/order/purchase_order_detail.html
+++ b/InvenTree/order/templates/order/purchase_order_detail.html
@@ -327,7 +327,7 @@ $("#po-table").inventreeTable({
         {
             sortable: true,
             sortName: 'part__MPN',
-            field: 'supplier_part_detail.MPN',
+            field: 'supplier_part_detail.manufacturer_part_detail.MPN',
             title: '{% trans "MPN" %}',
             formatter: function(value, row, index, field) {
                 if (row.supplier_part_detail && row.supplier_part_detail.manufacturer_part) {