diff --git a/dataext/optional.go b/dataext/optional.go
index 7f2a4a3..6facff5 100644
--- a/dataext/optional.go
+++ b/dataext/optional.go
@@ -25,6 +25,7 @@ func (m *JsonOpt[T]) UnmarshalJSON(data []byte) error {
 		return errors.New("JsonOpt: UnmarshalJSON on nil pointer")
 	}
 
+	m.isSet = true
 	return json.Unmarshal(data, &m.value)
 }
 
diff --git a/goextVersion.go b/goextVersion.go
index 9aa9e67..dc4c574 100644
--- a/goextVersion.go
+++ b/goextVersion.go
@@ -1,5 +1,5 @@
 package goext
 
-const GoextVersion = "0.0.425"
+const GoextVersion = "0.0.426"
 
-const GoextVersionTimestamp = "2024-03-30T14:24:53+0100"
+const GoextVersionTimestamp = "2024-04-01T16:03:00+0200"