diff --git a/Samples/Controls.Net4/Subscriptions/ReadValueEditDlg.cs b/Samples/Controls.Net4/Subscriptions/ReadValueEditDlg.cs
index c101561eb..4aff8df06 100644
--- a/Samples/Controls.Net4/Subscriptions/ReadValueEditDlg.cs
+++ b/Samples/Controls.Net4/Subscriptions/ReadValueEditDlg.cs
@@ -85,10 +85,9 @@ public async Task<bool> ShowDialogAsync(Session session, ReadValueId valueId, IT
             valueId.AttributeId = Attributes.GetIdentifier((string)AttributeIdCB.SelectedItem);
             valueId.IndexRange = IndexRangeTB.Text;
 
-            if (String.IsNullOrEmpty(EncodingCB.Text))
-            {
-                valueId.DataEncoding = new QualifiedName(EncodingCB.Text);
-            }
+            valueId.DataEncoding = !String.IsNullOrEmpty(EncodingCB.Text)
+                ? new QualifiedName(EncodingCB.Text)
+                : QualifiedName.Null;
 
             return true;
         }