diff --git a/dataext/optional.go b/dataext/optional.go
index b4667f7..ed89bf8 100644
--- a/dataext/optional.go
+++ b/dataext/optional.go
@@ -3,6 +3,7 @@ package dataext
 import (
 	"encoding/json"
 	"errors"
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
 )
 
 type JsonTwoWayMarshal interface {
@@ -10,7 +11,11 @@ type JsonTwoWayMarshal interface {
 	json.Unmarshaler
 }
 
-type JsonOpt[T JsonTwoWayMarshal] struct {
+type JsonOptType interface {
+	JsonTwoWayMarshal | ~string | ~bool | langext.NumberConstraint
+}
+
+type JsonOpt[T JsonOptType] struct {
 	isSet bool
 	value T
 }
@@ -25,7 +30,7 @@ func (m JsonOpt[T]) MarshalJSON() ([]byte, error) {
 		return []byte("null"), nil
 	}
 
-	return m.MarshalJSON()
+	return json.Marshal(m.value)
 }
 
 // UnmarshalJSON sets *m to a copy of data.
@@ -34,7 +39,7 @@ func (m *JsonOpt[T]) UnmarshalJSON(data []byte) error {
 		return errors.New("JsonOpt: UnmarshalJSON on nil pointer")
 	}
 
-	return m.value.UnmarshalJSON(data)
+	return json.Unmarshal(data, &m.value)
 }
 
 func (m JsonOpt[T]) IsSet() bool {
diff --git a/goextVersion.go b/goextVersion.go
index 5df8ad4..8fc3c96 100644
--- a/goextVersion.go
+++ b/goextVersion.go
@@ -1,5 +1,5 @@
 package goext
 
-const GoextVersion = "0.0.419"
+const GoextVersion = "0.0.420"
 
-const GoextVersionTimestamp = "2024-03-23T17:49:56+0100"
+const GoextVersionTimestamp = "2024-03-23T18:01:41+0100"