diff --git a/designer-chart/src/main/java/com/fr/extended/chart/UIComboBoxWithNone.java b/designer-chart/src/main/java/com/fr/extended/chart/UIComboBoxWithNone.java
index 0459cd710..65e7bbb43 100644
--- a/designer-chart/src/main/java/com/fr/extended/chart/UIComboBoxWithNone.java
+++ b/designer-chart/src/main/java/com/fr/extended/chart/UIComboBoxWithNone.java
@@ -23,7 +23,7 @@ public class UIComboBoxWithNone extends UIComboBox {
     }
 
     protected void setDefaultSelectedItem() {
-        setSelectedItem(null);
+        setSelectedItem(StringUtils.EMPTY);
     }
 
     @Override