diff --git a/src/main/java/org/minimalj/model/properties/ChainedProperty.java b/src/main/java/org/minimalj/model/properties/ChainedProperty.java
index <HASH>..<HASH> 100644
--- a/src/main/java/org/minimalj/model/properties/ChainedProperty.java
+++ b/src/main/java/org/minimalj/model/properties/ChainedProperty.java
@@ -57,6 +57,9 @@ public class ChainedProperty implements PropertyInterface {
 		Object value1 = property1.getValue(object);
 		if (value1 != null) {
 			property2.setValue(value1, value);
+		} else {
+			throw new NullPointerException(
+					property1.getName() + " on " + property1.getDeclaringClass().getSimpleName() + " is null");
 		}
 	}
ChainedProperty: don't allow set on null objects