diff --git a/src/frontend/src/components/editors/NotesEditor.tsx b/src/frontend/src/components/editors/NotesEditor.tsx
index 667cdd1ae5..058c3e4046 100644
--- a/src/frontend/src/components/editors/NotesEditor.tsx
+++ b/src/frontend/src/components/editors/NotesEditor.tsx
@@ -209,7 +209,7 @@ export default function NotesEditor({
         const sibling =
           mdeInstance?.codemirror.getWrapperElement()?.nextSibling;
 
-        if (sibling != null) {
+        if (sibling != null && editable != false) {
           EasyMDE.togglePreview(mdeInstance);
         }
       }
diff --git a/src/frontend/src/pages/purchasing/PurchaseOrderDetail.tsx b/src/frontend/src/pages/purchasing/PurchaseOrderDetail.tsx
index f8295065c9..7828433d6f 100644
--- a/src/frontend/src/pages/purchasing/PurchaseOrderDetail.tsx
+++ b/src/frontend/src/pages/purchasing/PurchaseOrderDetail.tsx
@@ -410,7 +410,13 @@ export default function PurchaseOrderDetail() {
       NotesPanel({
         model_type: ModelType.purchaseorder,
         model_id: order.pk,
-        has_note: !!order.notes
+        has_note: !!order.notes,
+        // TODO @matmair - change API to include a "locked" attribute that we can check here
+        editable:
+          order.status == poStatus.COMPLETE &&
+          !globalSettings.isSet('PURCHASEORDER_EDIT_COMPLETED_ORDERS')
+            ? false
+            : undefined
       })
     ];
   }, [order, id, user]);
diff --git a/src/frontend/src/pages/sales/SalesOrderDetail.tsx b/src/frontend/src/pages/sales/SalesOrderDetail.tsx
index 9fc6317929..ccec5f0832 100644
--- a/src/frontend/src/pages/sales/SalesOrderDetail.tsx
+++ b/src/frontend/src/pages/sales/SalesOrderDetail.tsx
@@ -448,7 +448,13 @@ export default function SalesOrderDetail() {
       NotesPanel({
         model_type: ModelType.salesorder,
         model_id: order.pk,
-        has_note: !!order.notes
+        has_note: !!order.notes,
+        // TODO @matmair - change API to include a "locked" attribute that we can check here
+        editable:
+          order.status == soStatus.COMPLETE &&
+          !globalSettings.isSet('SALESORDER_EDIT_COMPLETED_ORDERS')
+            ? false
+            : undefined
       })
     ];
   }, [order, id, user, soStatus, user]);